MessageProcessor: Use raw zmq socket

makes transition to CurveZMQ easier

removes some cron and timeout functionality, will be re-added when required
I think that it is not good idea to have separate thread only for timer. It is better to use event-driven reactor, use http://czmq.zeromq.org/manual:zloop or just zmq_poll.

> When no requests are coming in, no cron tasks are processed as well.
I do not know details about cron but I expects that we need to run cron after specific time and before we receive any message after that moment. So it should be sufficient to run cron after receiving message but before processing it (ProcessCron will be on line 185).