I've added the IPV4ONLY socket option and put some tests in socket_spec.rb. I've also removed the int_option? method from socket.rb as it does not appear to be used anywhere.
When I ran the test suite a few pre-existing tests failed (not as a result of my changes). I haven't done anything about them. I tested using the current ffi-rzmq master code and libzmq.so.3.0.0 on both Ruby 1.9.3-p125 and JRuby 1.6.7.
Add socket option IPV4ONLY
Remove unused int_option? method
Change ZMQ::Util to a class and remove includes for old module. ZMQ::…
…Util is a singleton class.