Working on unit tests. Found bugs in TCP and UDP. ByteBuffer returns a (signed) short for ports, but they are valid 0-65535, not -32768-32767. Convert possibly negative ports from BB to positive ints using a bitmask.

2 - Move the learning switch table outside of the IOFSwitch and into the LearningSwitch module.
3 - Create a REST API for the LearningSwitch module to get the learned table. Available at "/wm/learningswitch/switch/{DPID or 'all'}/json".