State automatically saves on favorites changes

Also prevents repeated saves when no modifications have occurred. Only
lightly tested so far.
Merge branch 'hotfix-2.0.1'
Merge branch 'master' into advanced-save
Save delays to improve performance

Acts immediately on deactivate/close to ensure no changes are lost. Save
intelligently only updates necessary properties.
Save timer created once
Update storage system
More robust version management
Merge branch 'advanced-save' into develop