desktop-file-validate: Trailing semicolons have been downgraded to optional

https://bugs.freedesktop.org/show_bug.cgi?id=76902
Approved by David Faure and Ryan Lortie
Add Cinnamon to list of registered environments.

https://github.com/linuxmint/Cinnamon

https://bugs.freedesktop.org/show_bug.cgi?id=73497
Add EDE to the list of desktop environments

https://bugs.freedesktop.org/show_bug.cgi?id=56353