CN/TrEx 2 -- CN Aggregate Group

CentralNotice will now create a 'CentralNotice' aggregate group
under which banner messages will be placed for translation.

PS 5 & 6 - now with rebase madness
PS 7 - W/ Nikerabbit's comments from PS4
PS 9 - Rebase

Change-Id: I5edd16d9461c6e4147294497c8b389d7d1197291