Merge pull request #75 from hintjens/master

Fixed zmq_poll man page
Fixed el5/el6 deps in RPM spec file
Merge pull request #76 from amuraru/master

Fixed el5/el6 deps in RPM spec file
Fix assertion failed in tcp_listener.cpp:58

Closes issue LIBZMQ-504
Merge pull request #77 from BoresExpress/master

Closes issue LIBZMQ-504
Revert "Fix assertion failed in tcp_listener.cpp:58"

This reverts commit a87aed284e10accc88456498d231628d84d41f6a.
Causes an assertion failure: s != retired_fd (tcp_connecter.cpp:271)