Fix generated POSIX-only constants

	modified:   lib/POEx/ZMQ/Constants.pm
	modified:   tools/gen_zmq_constants
POD
POD, cleanups

	modified:   lib/POEx/ZMQ/Constants.pm
	modified:   lib/POEx/ZMQ/FFI/Context.pm
	modified:   tools/gen_zmq_constants
v0.002002

  - POEx::ZMQ::Constants fixes