Implement the Reply and Emote commands on HipChat adapter

I set up the Reply and Emote commands to work on the HipChat adapter, and for the corresponding commands on the Response class to call out to the originating adapter.

I've tested this on live HipChat and it seems to function properly.  I mostly just copy pasted the code from the reply methods and modified them as needed, so there is a minor refactoring opportunity there, but I'm not entirely sure which way one would want to go with it.