Arakoon 347 2

This concerns the extra logging.
Added the following sections: client_protocol, paxos & tcp_messaging.

I also took a look at https://github.com/Incubaid/arakoon/commit/4a89d1f01de3a5eb246502a9a1a57ab372de1b75 (347 from Moataz).
Main things I don't have, judged from a quick scan over his commit would be:
- I have not added the logging to mem_store.ml;
- I did not remove the log_o logging in sync_backend.ml
- I have not explicitly logged n and i in the paxos related files. That information should be mostly available from the incoming and outgoing messages.

Passes CI tests.