(PECL zmq >= 1.0.4)
ZMQSocket::unbind — Unbind the socket
   Unbind the socket from an endpoint. The endpoint is defined in format transport://address where 
   transport is one of the following: inproc, ipc, tcp, pgm or epgm.
  
dsn
       The previously bound dsn, for example transport://address.
      
Returns the current object. Throws ZMQSocketException on error.