Merge pull request #865 from jemc/master

Problem: Low-level CZMQ primitives needlessly use extended container zlistx.
Rebuilt man pages
Merge pull request #866 from hintjens/master

Rebuilt man pages
Problem: zpoller man page didn't explain how to do infinite wait

Solution: fixed man page
Merge pull request #867 from hintjens/master

Problem: zpoller man page didn't explain how to do infinite wait
Implement a definitive czmq build for cygwin targets.
Merge pull request #868 from DaiyuHurst/master

Implement a definitive czmq build for cygwin targets.