Update permission types API controller to also return description for each permission type.
Update permission types API controller to also return description for
each permission type.

StackStorm/st2,Plexxi/st2,Plexxi/st2,nzlosh/st2,nzlosh/st2,nzlosh/st2,StackStorm/st2,StackStorm/st2,nzlosh/st2,Plexxi/st2,tonybaloney/st2,tonybaloney/st2,StackStorm/st2,Plexxi/st2,tonybaloney/st2