Add Google to the AUTHORS file.

Change-Id: Ie1c882a622cf8f4de12230367b11a644d3040ae8
Reviewed-on: http://gerrit.dmdirc.com/2642
Automatic-Compile: DMDirc Build Manager
Reviewed-by: Greg Holmes <greg@dmdirc.com>

AUTHORS

 # This is the official list of DMDirc Developers for copyright purposes.
 Chris Smith <chris@dmdirc.com>
+Google Inc.
 Greg Holmes <greg@dmdirc.com>
 Shane McCormack <shane@dmdirc.com>
-Simon Mott <simon@dmdirc.com>
+Simon Mott <simon@dmdirc.com>