* Initial work for creating a rules.json file that can be used in both the frontend and backend.

* Address some review comments.

* Make rules.json useable in both frontend and backend
- deprecate hard/soft rules from backend
- replace 'fuzzy rule' teminology

* Fix lint errors

* Remove print

* Fix another merge conflict

* add installation of node modules in setup.sh

* Change various

* Restore files

* Add script to randomize library banner.

* Fix #1979 : Right scroll button of the library carousel is flushed to the right at 514px (#2021)

* Fixes #1979

* Added comment

* Updated the comment

* Fix map width on narrow viewport (#2046)

* Add new banners to library graphics folder.

* Fix spanish translations (#2067)

* Fixing library translations

* Missing quote

* Adding the new library translation to tests

* Divided editor suite into mainEditor and editorFeatures. #2065 (#2070)

* Fix #461: introducing milestone #1 for feedback message emails. (#2071)

* Add FeedbackMessageEmailDataModel and constants for feedback message email service.

  - Modifies core/storage/feedback/gae_models.py for adding FeedbackMessageEmailDataModel.
  - Modifies feconf.py to add relevent constants, default values for feedback message email service.

* documentation and comment line changes for better understanding of code.

* Fixed issue with flickering on profile page

* Handling review comments.

* Fix #2075: interests not wrapping on profile page (#2079)

* Fixed issue 2075, interests not wrapping

* Changed spacing to match standards.

* Removed extraneous comment.

* Fix part of #1366 : create continuous job for creator dashboard statistics (#1891)

* Create user model for dashboard stats

* Reuse UserStatsModel instead of creating new one

* job for continuous computations, yet to be tested

* Update existing job to calculate user-specific stats

* Address initial review comment

* Address review comments

* Revert model changes; commented out failing tests for now

* Fix failing backend tests; changes to map

* Minor fix

* Basic Integration test for dashboard stats

* Address review comments

* Added name to TODO

* Add total_plays test by computation through job

* Complete dashboard tests for single exp owner

* tests for multiple owners

* Fix lint errors; add comments

* Fix to map; Address review comments

* Fix alphabetic ordering of imports

* Service to get total unresolved answers for exp

* Add a task queue for backups. (#2081)

* Fix part of #461: Implement emails taskqueue for handling feedback message emails (milestone 2) (#2077)

* Implement emails taskqueue for handling feedback message emails.

  - Added a new queue in queue.yaml
  - Added handler function in feedback.py (Not implemented yet)
  - Added function for adding task in taskqueue in gae_taskqueue_services
  - Added taskqueue related test in gae_taskqueue_services_test
  - Added function for getting pending task objects of a taskqueue in test_utils
  - Added task handler function url in feconf and main
  - Removed indexing from feedback_messages property in UnsentFeedbackEmailModel

* separate logic level implementation of taskqueue from platform

feedback_services contains function to add task in taskqueue, which
calls the taskqueue service to add particular task in queue.
This separation provides interface between function which communicates with GAE
and function which is used by other code.

* Some minor changes in 'emails' taskqueue related functions.

* Add information about parameters of enqueue_task() in taskqueue_services

* Typos in parameters information of enqueue_task() in taskqueue_services

* Remove unneeded config properties in order to improve performance.

* Fix backend test.

* Simplify backend test.

* Fix #1974: Added '==' and '!=' as bad patterns for js files. (#1980)

* Added '==' and '!=' as bad patterns for js files.

* Corrected bad patterns in js files. #1974

* Modified bad pattern and fixed linting issues.

* Fixed bad pattern issues.

* Modified pre_commit_linter to support new bad patterns.

* Modified schema of BAD_PATTERNS and BAD_PATTERNS_JS.

* Added exclude_files for ' != ' pattern.

* Create method to fetch user stats data

* Add unit test for service

* Code fixes

* Fix lint issues

* Remove js from library.js and library.html in favor of var.

* Fix backend tests.

* Address notes.

* Fix lint indenting.

* Address style notes

* Fix lint

* Fixed typo in css file.

* Hide the exploration graph if there is only one card in the exploration. (#2085)

* Hide the exploration graph if there is only one card in the exploration.

* Fix test errors.

* Fix e2e tests.

* Fix #2078: prevent unsaved changes from being lost when editing a state name. (#2084)

* Address review comments

* Use get_multi instead of get

* Address review comments

* Fix lint errors

* Revert unresolved answers part

* Revert unresolved answers part

* Added share links to the bottom of the terminal exploration card, Created a square icon for embed link

* fixed a comma

* fix typo

* Fix continue interaction

* Add more tests for AnswerClassificationService

* Fix an error where null interactions were not being handled correctly.

* Fix lint error.

* Update pre-push hook to correctly handle copied/renamed filediffs.

* Add e2e tests for i18n. Address some review comments.

* Fixes #1931: Added caption functionality (#2104)

* Resolve comments

* small fix

* Add more tests for AnswerClassificationService

* Fix #1901: move terms/privacy links to the footer. Also remove redundant /participate page, add redirect links, and add 'contact us' link. (#2114)

* Remove redundant /participate page. Add redirect links.

* Move terms and privacy links to the footer. Add 'Contact Us' link.

* Remove the 'contributors' field completely from the exploration summaries.

* Implemented a version of stats_services.get_top_state_rule_answers to
fetch answers for multiple explorations simultaneously, providing a more
efficient means of getting top answers for multiple explorations using a
single database call.

* Added Indonesian translation

* Fixed: removed duplicate keys

* Fixed: space before '('

* Fixed: add space between ':' and quote

* Fix part of #1366: Controller for creator dashboard (#2096)

* Changes to dashboard controller

* Removing unresolved answers for now

* Fix name of method

* Address initial review comments

* Re-use existing exp_summaries method

* Address review comments

* Address some of the review comments

* Fix failing tests

* Fix failing dashboard test

* Address few review comments; fix failing tests

* Revert changes to feedback_services; add test for multi

* Modify code to test better

* Add test when both models are None

* Add tests to handle cases when models are None

* Address review comments

* Call feedback_services method instead of directly accessing model

* Addressed review comments (except 1 regarding testing). This alters the
data structures used throughout the multi-exploration, top-answer
fetching pipeline.

* Addressed final review comment (added a new test to ensure multiple rule
types are handled correctly).

* Refactor HistoryServices to allow diff computation for a single commit.

* Remove the standard navbar tabs from the collection player. (#2133)

* Fix milestones 3 and 5 of #921:
Add button to restart preview mode from initial state.
Show a list of all current parameter values in preview mode.

* Pull exploration diff computation into a separate service.

* Add another test

* Fix error in creating th e combined changelist. Remove unused method.

* Adding qqq.json file with explanation of translation keys.

* Spelling errors

* Address review comments.

* (Partially) Fix #2047: implement performance testing framework. (#2068)

* WIP #2047: Implemented selenium + browsermob-proxy to fetch us performance metrics

* Implement getting stats from data and basic tests

* Added timings metrics for page load

* Implemented stats for cached state (return users), wrote tests for splash, fixed issues

* Modified backend_tests to include performance tests

* Added separate script for performance tests, integrated it with travis and addressed review comments.

* Change email addresses for Travis-CI notifications. (#2141)

* Split the visualization parts of the exploration editor history tab into individual directives.

* Fix #2120: add translate attribute to corresponding buttons on the Teach page (#2132)

* #2120 Create and Browse button translated into Espanol

* added action_create and action_browse i8n key-values for splash and teach page

* added action_create and action_browse i8n key-values for splash and teach page

* i8n splash and teach buttons made consistent

* Address review comments.

* Guard against bad request data.

* Fix e2e test.

* Fix #2035 Replace glyphicons with material icons (#2087)

* Fix #2035 Remove glyphicons

* Fix #2035 Remove glyphicons

* Fix #2035 Remove glyphicons and update scripts/pre_commit_linter.py

* Fix #2035 Remove glyphicons and update scripts/pre_commit_linter.py

* Fix #2035 Replace glyphicons with material icons

* Fix #2035 Replace glyphicons with material icons

* Fix #2035 Remove glyphicons

* Fix #2035 Remove glyphicons

* Fix #2035 Remove glyphicons and add style for unaligned material-icons

* Fix #2035 replace glyphicons with material icons

* Fix #2035 remove glyphicons and adjust size of icons on profile page

* Update oppia.css

* Fix #2035 Remove glyphicons

* Update profile.html

* Update profile.html

* Fix #2035 Remove glyphicons

* Fix #2035 and replace glyphicon from #921

* Fix #2035 Remove glyphicons

* Fix #2035 and remove duplicate styles

* Fix #2035 Remove glyphicons

* Fixes #2121: Remove I18N_LIBRARY_LANGUAGES_* keys from translation files. (#2147)

* Fix error when an exploration is deleted

* Fix part of #1366: Frontend services and controller for creator dashboard (#2126)

* Create and use DashboardBackendApiService

* Remove http Dependency injection in controller

* Removed scope and rootScope from Spec

* Modify DashboardSpec according to api service

* Address review comments

* Added warning when request fails

* Use string as an warning

* Display warning only if 500,404,401,400

* Remove 400, 401 from error statuses

* Warning only on server error

* Update DashboardBackendApiService.js

* Update DashboardBackendApiServiceSpec.js

* Update DashboardBackendApiService.js

* Update Dashboard.js

* Try and adding 401 to warning status codes

(Will be reverted if tests fail)

* extract hard-coded value to constant

* Reintroduced the old get_multi answer path since the new path is not
entirely backward compatible with legacy answer stats methods that
depend on subtle ordering details of the old path. Fixed ordering when
querying for answers for multiple states in the same exploration.
Removed the count argument limiting the number of answers returned for
get_top_state_rule_answers and get_top_state_rule_answers_multi.

* Resolving problems post-merge.

* Check exp_summaries are not None; revert prev commit

* Address review comment; revert prev commit

* Fix lint

* Use filter for collection summaries too

* {{Change toolbar to the top}}

* Fix #2091 Adjust footer on smaller screens (#2149)

* Fix #2091 Adjust footer on smaller screens

* Fix #2091 Adjust footer on smaller screens

* Fix #2091 Adjust footer styles on smaller screens

* Fix #2091 Adjust footer styles on smaller screens

* Fix #2091 Adjust footer styles on smaller screens 

Adjust footer by adding 30px padding to match expected behavior on smaller screens

* Part of #461: implement send_feedback_message_email function in feedback_services (#2145)

* implement send_feedback_message_email function in feedback_services

* Use synchronous transactional service when creating or modifying instance of UnsentFeedbackDataModel

* Change location of create_or_modify logic of UnsentFeedbackDataModel to feedback_services

* create FeedbackMessageReferences domain object for storing and retrieving feedback message references

* making code nit and clean

* Fix part of #1366: Frontend view for creator dashboard (#2151)

* Create top row with hardcoded data for now

* Exploration list view

* Fixes to view

* Restore text when dashboard is empty

* Address initial review comments

* Added feedback threads count

* Add last updated

* Made explorations clickable; css fixes

* Sort explortions aphabetically

* Add featured badge to against title

* Fixes to code

* Fix failing frontend test; featured exploration

* Fix alphabetic ordering of current css

* Fix merge conflicts with develop

* Replace dummy values with backend data

* Fix sorter method on explorations list

* Addressed a review comment.

* Fix #2089: Text field for Preferred Languages in the Preferences page don't display well on mobile phones. (#2152)

* Fixes #2121: Remove I18N_LIBRARY_LANGUAGES_* keys from translation files.

* Fix #2089: Text field for Preferred Languages in the Preferences page don't display well on mobile phones.

* Changing the dropdown width to 100%

* Fix #2047: introduce multiple PageSession object (new). (#2139)

* Fix #1857:Add a flag to enable minified version locally for developers. (#1919)

* added flag that can be used to run oppia in minified version as in production

* set a dynamic environment variable that changes depending on the flag

* added option to install numpy if we decide even when the flag prod_env is passed in

* update MINIFICATION and DEV_MODE reference where appropriate

* Fixes #2117: added span element for creator dashboard text (#2166)

* Create pt-ptfinal.json

* Fix #2138: make performance tests declarative. (#2150)

* Implemented Multiple PageSessionMetrics.

* Added many timing metrics

* Implement basic structure for declarative tests (POC).

* Implemented helper methods for tests, restructured the tests

* Refactor the sharing-links directive to explicitly pass in the exploration id. (#2172)

* Fix missing text next to player feedback checkbox. (#2177)

* Read featured activities from a list, in order to reduce loading time in the library. (#2105)

* Read featured activities from a list, in order to reduce loading time in the library.

* Remove activities from the featured list when they are deleted or unpublished.

* Add tests.

* Address review comments; fix backend test.

* Address review comments; refactor code to drop the notion of new ids representing activities.

* Remove unused constants in feconf.

* Refactor backend code to reduce direct dependencies on activity_domain.

* Small fixes.

* Address review comments.

* Address remaining review comments.

* Fix #1801: modify publish modal to be more visually appealing (#2169)

* Rebuilding branch due to multiple issues with rebasing

* Refactor everything to deal with multiple issues from being off with development branch

* Fix linting issues

* Removed all dashboard related changes to leaave only publish modal updates

* Remove uncessary comma

* Remove dashboard code from sharing links directive

* Update dashboard.py from latest develop

* Fix linting issue

* Fixing per review comments

* Removing unsed translations.

* Ensure all i18n json files have the same keys. (#2180)

* Ensure all i18n json files have the same keys.

* Don't fail tests due to missing i18n keys.

* Fix some nits. Move/replace congratulatory image to general folder in accordance with deploy process.

* Alphabetize strings in i18n json files, and update missing strings in qqq.json.

* Put graph visualization in saving diff (#2175)

* Put graph visualization in saving diff

* Added check for different versions

* Remove backend change list summarization.

* Hide diff behind show changes button

* Add support for gadgets

* Fix gadgets changes

* Fix #2092: Placeholder sometimes shows 'I18N_PREFERENCES...' on subject interests and preferred languages. (#2183)

* Fix #2092: Placeholder sometimes shows 'I18N_PREFERENCES...' on subject interests and preferred languages.

* modified function and variable names, added comments for the function

* Add Portuguese translations to feconf, sort the existing ones, and remove unused ones.

* Fixes #2013

* Various minor fixes: change "featured explorations" to "featured activities" in the library; change the wording for the "featuring" functionality in the exploration settings tab; add missing strings to qqq.json; remove "neither, thanks" option from the activity creation modal. (#2191)

* Fix view all button flushed right appearance

* Fix #2154: xvfb not found. (#2184)

* Remove xvfb-wrapper from performance tests, install xvfb for all users

* Moved xvfb installation to performance tests

* Minor fix

* Addressed review comments

* Added name in todo

* Fix #2164: Expand exploration summary tile width to match collection summary tile width (#2182)

* Modify exploration summary tile width to 214 px

* Fix missing 214px areas for tiles

* Add comment about implementing margin change

* Fix #2198: rename ClassifyMatches back to FuzzyMatches. (#2204)

* Add calc compatible CSS

* Creation of donation page (#2200)

* Add Portuguese translations. (#2190)

* Create pt-ptfinal.json

* Add Portuguese translations to feconf, sort the existing ones, and remove unused ones.

* Created Donate page. Changed TOPNAV and footer to include links to Donate page.

* Added donate.html

* Addressed PR comments

* Addressed comments in PR request.

* Addressed PR comments.

* Update donate page image.

* Fixes Review comments

* fixed pattern issues

* Added fix for larger screens

* Fix #2144: Fixes language dropdown positioning issue. (#2205)

* Modified media query max width to 1230. #2144

* Modified browser width for protractor tests.

* Fixes 2023

* Fix 2113: Added Wide option for non-terminal, non-narrow cards (#2158)

* Fix #461: completion of implementing feedback message email service (#2171)

* completion of implementing feedback message email service
  - implemented emails taskqueue handler function.
  - implemented user property for choice of receiving feedback message emails.
  - implemented frontend checkbox for above property.
  - added required backend, frontend and e2e tests.

* fixes for feedback message email service
  - feedback message email should not be sent if message is from author himself
  - fixes for failed backend test

* fix backend test for feedback controller

* optimizations in feedback message email service and some documentation changes.

* implement proper structure of processing and flushing of taskqueue task for backend testing.

* change if condition to be more verbose and understandable.

* small changes to make feedback message email system error proof.

* Add test at controller level to check that correct email body is sent for feedback messages.

* some nit changes in the code

* Remove unnecessary CSS.

* Fix #2108: Remove rounded corners of select2 dropdown. (#2210)

* Fix spelling error.

* Fix exploration ids in player sharing

and small style fix

* Adjust width of group headers to account for the increase in width in the activity summary tiles.

* fix alignment of sharing links

* Update translations.

* Remove unneeded div.

* Fix part of #1366: Card view for creator dashboard (#2170)

* Add card view to dashboard

* Display view toggler only for explorations

* Use track by in repeater

* Fix alphabetic ordering of css properties

* UI fixes

* Fix delayed hide/show of views

* Add sharing links to card view

* Revert "Add sharing links to card view"

This reverts commit 2eaa5bc.

Revert adding sharing links with outdated directive

* Add sharing links to dashboard card view

* css fixes for card view

* Add translation for last updated

* Minor fixes to view

* 4 cards per row; fix margin of container

* Fix dashboard tooltip being in the wrong font. (#2214)

Fix dashboard tooltip being in the wrong font.

* Update AUTHORS, CONTRIBUTORS and credits.

* Bump the version number to 2.3.1 and update the changelog