Extend zmq::wsa_error_to_errno()

The list of error codes is taken from zmq::wsa_error_no(). Most of the
new WSA error codes result in EFAULT, but some return a more specific
value (even EAGAIN).

Backport of zeromq/libzmq#1072
Merge pull request #83 from olafmandel/backport_1072

Extend zmq::wsa_error_to_errno()