Improve getPath() functions. Null is no longer returned anywhere. Instead, we use empty Path objects to indicate a path was not found.

Allow retrieval of VLAN tag from packet-in match. The VLAN tag might be here if the switch popped the VLAN tag from the packet itself prior to encapsulating it in the packet-in message.

Add new detailed-match property to define source and destination addresses to match on in each layer. Also add in-port as an optional match for the existing match property.

Don't use statistics service to get link speed. This can be derived from the IOSwitchService more efficiently. Remove link speed function from IStatisticsService.

Change log levels of frequent, unnecessary logs to debug. Were previously warn. Add new RoutingManager to properties

Restrict access to TopologyInstance constructor and compute() functions. Other public functions should also be changed to private or protected.

Create RoutingManager that is separate from TopologyManger. It hooks into TopologyManager via new ITopologyManagerBackend, butmakes it much more obvious that the TopologyManger and TopologyInstance is responsible for much of the routing. Before this change, the actual 'routing' and 'path-finding' implementation location wasn't very clear.

More REST API updates. Added JsonObjectWrapper class to wrap types that Jackson will serialize into arrays (illegal if outer type in JSON).