Update docs
Merge pull request #334 from claws/update_docs

Update docs
beginning support for zmq_proxy_steerable and improved backwards compatibility
zproxy - added a free to response from terminate command
Merge pull request #335 from Talksum/master

starting support for zmq_proxy_steerable and improved backwards compat
zproxy changes for better handling of different libzmq versions
zproxy comment cleanup
zproxy - updating docs - will hand edit into nicer format later.
Merge pull request #336 from Talksum/master

zproxy backwards compatibility refactor
Removed bogus assertion of buffer alignment
Merge pull request #337 from hintjens/master

Removed bogus assertion of buffer alignment
zproxy terminate will now time out and assert instead of infinite hang on problem
Merge pull request #338 from Talksum/master

zproxy_terminate will now time out and assert instead of infinite hang