Added binary data (uint8) conversions
Added size_t conversions
Added zmq_recv, zmq_send
Added test_zmq_req_rep

- Needs to test multipart messages
- Needs to test other socket types
Added tests_zmq_req_rep_multipart
Added PUB/SUB PUSH/PULL examples
Fixing Ash's mess.

Conflicts:
	lib/zmq_recv.m
	lib/zmq_send.m
	src/core/zmq_send.c