[aerogear-dev] GCM Topics Support Cont.

So the current PRs for Topics use them automatically when you subscribe to a category. Google doesn't support delivering messages to a subset of users over a topic. UPS has the ability to deliver messages to subsets of category subscribers (via alias and deviceType). I think that a suitable workaround for this would be if a message is sent to a category, and there is a topic available, AND the message isn't filtered based on alias or deviceType then use the topic. Otherwise the message should be treated "normally" and use registrationId based sending (like we do now). wdyt? And as an aside, can you guys think of other use cases where the all or nothing nature of topics might be a problem?