[aerogear-dev] UPS Categories going forward

Y'all, Since I now have a GCM Topic PR up I figure it is time to revisit beefing up categories a bit. Before we discussed enhancing the server and client APIs so one could subscribe and unsubscribe to topics without unregistering and reregistering. This will require a new endpoint on UPS and new code in all the libraries We also discussed adding the ability to "route" messages to specific handlers based on what category the message was sent to. This will require adding a field to all push messages that don't use GCM topics. It will also require updates on the client code. As an aside there is also GCM support on iOS, but it is much more complicated to set up.