[fix bug 1010593] Add back option to merge groups in /admin.
[fix bug 1010593] Add back option to merge groups in /admin.

mozilla/mozillians,justinpotts/mozillians,safwanrahman/mozillians,brian-yang/mozillians,chirilo/mozillians,justinpotts/mozillians,ChristineLaMuse/mozillians,johngian/mozillians,fxa90id/mozillians,akarki15/mozillians,mozilla/mozillians,justinpotts/mozillians,safwanrahman/mozillians,johngian/mozillians,akarki15/mozillians,akatsoulas/mozillians,brian-yang/mozillians,johngian/mozillians,fxa90id/mozillians,safwanrahman/mozillians,chirilo/mozillians,anistark/mozillians,brian-yang/mozillians,brian-yang/mozillians,anistark/mozillians,hoosteeno/mozillians,safwanrahman/mozillians,fxa90id/mozillians,chirilo/mozillians,ChristineLaMuse/mozillians,hoosteeno/mozillians,justinpotts/mozillians,hoosteeno/mozillians,akarki15/mozillians,anistark/mozillians,akatsoulas/mozillians,chirilo/mozillians,mozilla/mozillians,akarki15/mozillians,johngian/mozillians,fxa90id/mozillians,mozilla/mozillians,ChristineLaMuse/mozillians,hoosteeno/mozillians,akatsoulas/mozillians,anistark/mozillians,akatsoulas/mozillians