Implement a toolbar shown in the bottom part of the tree-view. The toolbar is especially meant for new users to give an easy, visual, access
to the more important commands.

Make the treeview resizable and shows the resize cursor only when panes are actually resizable.

Add config mechanism to disable a plugin by setting config.<plugin-name> = false.

Improve the "detect indent" plugin to take into account the syntax and exclude comments for much accurate results.

Add command root:close-all to close all the documents currently opened.

Show the full path filename of the active document in the window's title.

Fix problem with user's module reload not always enabled plus other minor fixes.