Problem: don't know own UUID

- needed for logging, to correlate events
- new method, zyre_uuid() returns this
Fixed zre_msg and zre_log_msg for Windows

- regenerated with zproto using CZMQ_EXPORT
Added zyre_set_port () method

Fixes #167
Merge pull request #166 from hintjens/master

Added zyre_uuid and fixed Win32 exports