Merge pull request #1 from lebouquetin/master

Allow to delete / archive folders + fixes deleted / archived items count
Merge pull request #2 from lebouquetin/master

Option to show/hide contents in left side treeview
Merge pull request #3 from lebouquetin/master

add first implementation of unit and functionnal tests
fixes the new treeview content root call
improve test coverage + fixes bug #40