GUACAMOLE-1110: Merge changes adding a guacd service group.
GUACAMOLE-1110: Merge changes adding a guacd service group.


apache/guacamole-server,mike-jumper/incubator-guacamole-server,apache/guacamole-server,mike-jumper/incubator-guacamole-server,glyptodon/guacamole-server,mike-jumper/incubator-guacamole-server,mike-jumper/incubator-guacamole-server,apache/guacamole-server,glyptodon/guacamole-server,glyptodon/guacamole-server