Threading restructure

Hmm, where to start? 

* Removes resque, blather, eventmachine and em-synchrony, and thin
* uses xmpp4r and webrick for Jabber and HTTP services instead
* uses threads rather than an evented architecture

This is aimed at fixing issues like #115, #133, #143 and probably others (I'll add them in as I find them). Where it doesn't directly address those issues it should at least be an architecture in which debugging and handling them is much easier.

Although I've been testing this code as I go, problems with hardware over the last week mean that the testing hasn't kept up with some of the recent changes on this branch. More testing will be needed with real-world data loading.