Add ports overlays, metasets for Cinnamon, Gnome3, and Mate

If this merge needs to be cancelled for any reason, and I need to make any changes please let me know.  The only thing I might consider changing here is to add cinnamon to unsupported desktops even though it is xdg-complaint.  It does not work without 3D hardware as the cinnamon2d session is broken and is a known issue.  I am still looking into that.  

For the mate ports i've tried to keep the same style as your other by adding the lite packages.  Mate is also currently very limited on the number of extras hence the lack of additional meta ports.  

With Gnome3 the lite package needs worked on upstream as it installs all of the extras anyway.  I can get with the freebsd gnome team on this if needed.  However some things such as gdm have to be installed for gnome3 unfortunately.  It does not have to be used but gnome-shell requires some files that gdm installs.