Updated MATE.

Hi,

Here is an update for MATE. Wish I'd seen the `testing` branch earlier, it would have saved me some time. Looks like you've cleaned up the code somewhat :-)

  * I've cleaned up the MATE package list that provide slightly less than a full MATE install but all the essential and useful stuff. I've added some applications that feature in GNOME3/Cinnamon that appear to be your preferred choices. I removed some MATE applications that are community contributed.
  * Currently `mate-bluetooth` requires `bluez4` which is now only available from the AUR. Therefore I've removed `bluetooth` from the features for MATE.
  * I've added `unrar` to the archivers, as `mate-file-archiver` recently added support for RAR 5.x.
  * I haven't update `cli_installer` as I'm not sure if that is still relevant?

Looking forward to seeing MATE in Antergos soon :-)

Regards, Martin.