ZAuth with null mechanism support
null allows all but blacklisted through
cleanup, stubs for other mechs
add self to authors...
Merge pull request #265 from cbusbey/null_mech

ZAuth with Null Security Mechanism
Fixed broken builds for zmq < 4.0.0
Merge pull request #266 from cbusbey/null_mech

Fixed broken builds for zmq < 4.0.0