Restore minimal Sundry category

Partial workaround for #7

Upgraders will still have a Sundry app folder in GNOME Shell, which can be removed by manually running something like dconf reset -f /org/gnome/desktop/app-folders/

The Sundry app folder is at least better than a X-GNOME-Sundry app folder.

New installs and everything else that don't use GNOME app folders won't have a Sundry app folder.

To reproduce the issue with a clean install

Install dconf-editor (this is an app that was previously in the Sundry app folder.)

Save the dconf output from #7 to old-menus.txt. Remove all the extra line breaks from the apps line.

$ dconf load / < old-menus.txt

You can also install and activate the applications-menu extension to see how the patch works with something that ignores GNOME app-folders.

Review

@klember Are you interested in reviewing this?

If you approve, I'll file for a String Freeze exception.