Updated .gitignore
Added ZMQ_IPV6 option, cleaned up setsockopt code, it was nasty
Various cleanups to test programs
Fixed use of deprecated zmq_init/term
Rewrote raw test completely
Rewrote completely, was bogusly testing EAGAIN
Lots of cleanups to self-tests
* Removed or truncated sleeps so the tests run faster
* Removed dependencies on zmq_utils
* Rewrote a few tests that were confusing
* Minor code cleanups
Fixed issue #499
Merge pull request #508 from hintjens/master

IPv6 related changes and cleanups to test cases