sort menu categories
Menu categoties were not sorted after being localized. This does not respect the order possibly changed by cinnamon-menu-editor, but neither do we do it for applications
Sort preference categories behind normal application categories
Remove move up/down buttons from cinnamon menu editor
sort menu categories as it is done in the menu applet (sort alpha, administration and preferences last)
On resetting the menu to system defaults: don't save a config file with only a link to system config
Merge pull request #3484 from Cobinja/sort-menu-cat

Sort menu categories