Evaluate post_chat.

[Morgul]

We either need to cleanup/add features to the post_chat module, or we need to remove it. In the past, we've talked about leveraging an XMPP server, like ejabberd instead of doing our own thing, but the more I think about it, the more there might be merit to implementing just the features we need.

@SkewedAspect/developers I'd like to know everyone's opinion on the post_chat module, and from there, we can make the decision about whether or not we keep it or remove it.