Remove unnecessary log in zsys_set_interface().
Merge pull request #653 from hintjens/master

Cleanups
Merge pull request #654 from ahhentz/to_merge

Remove unnecessary log in zsys_set_interface().
msvc build fixes. explicit casts required.
Merge pull request #656 from jossgray/msvc_build_fixes

msvc build fixes. explicit casts required.
Merge pull request #657 from hintjens/master

Catch common error of zsocket_set_xxx on zsock_t sockets
Merge pull request #658 from hintjens/master

Removing workaround for ZMQ #1169 as the problem no longer hits
Problem: dropped & in last patch, causing segfault

Solution: run 'make check' before pushing commits :-)