R1:574bc3ba31cc

First pass at decoupling Phabricator bot behavior from the protocol it's running on, this pulls the connection, reading, and writing functionalities out of the bot itself and into the adapter.

Summary:
Ugh, just wrote out a huge message, only to lose it with a fat-fingered ctrl-c. Le sigh.

First pass at decoupling the bot from the protocol. Noticeably absent is the command/message coupling. After this design pass I'll give that a go. Could use some advice, thinking that handlers should only create…