bump version

and adds a Makefile

Merge pull request nextcloud#350 from nextcloud/old-versioning-nc10

info.xml <owncloud>tag is required for apps that run on Nextcloud 9 and 10

Merge pull request nextcloud#318 from nextcloud/bump-version

bump version

9.0.5

8.2.8

8.1.10

8.0.15

9.0.5RC2

8.2.8RC2

Merge pull request nextcloud#287 from owncloud/fix-warning

fix undefined offset warning