Prefer libzmq.so.3 over libzmq.so

	modified:   lib/POEx/ZMQ/FFI.pm
Stop indexing tools/

	modified:   lib/POEx/ZMQ/Constants.pm
	renamed:    tools/zmq_constants.pl -> tools/gen_zmq_constants
use MetaNoIndex

	modified:   dist.ini
	modified:   lib/POEx/ZMQ/Constants.pm
	modified:   tools/gen_zmq_constants