Start implementing UDP support
Initial UDP implementation and basic listen/send/receive test.
Add tests for DatagramSocket#listen variations
Add tests for datagram/udp
Force interpreted mode for tests
Un-bonehead the listen same port multiple times test
Add configuration tests to UDP, and always return 'this' for method chaining
Add test for joining and leaving a multicast group
Bump vertx core, platform and testtools to 2.0.3-SNAPSHOT