o Make sure both pfds and mds are allocated or none. Otherwise   one might be left unallocated;
o Make sure both pfds and mds are allocated or none. Otherwise
  one might be left unallocated;

o clean history and decref sockets if allocation fails.

dsanders11/rtpproxy,sippy/rtpproxy,sippy/rtpproxy,dsanders11/rtpproxy,dsanders11/rtpproxy,sippy/rtpproxy