Improve requirements section in README

Fix click on root button in path bar

Merge branch 'dev'

Remove useless .orig

Update changelog

Update changelog

Fix typo in desktop id

Merge branch 'fix_#9'

Fix #9 by putting `after_cancel` in try/except block to catch the `ValueError` which is raised since Python 3.6.5 if there is nothing to cancel.

Update setupu.py, README and changelog

Improve extension management in save mode