Add some additional unit tests and change error status to null from NONE.  Some minor serializer cleanup

Add a debug REST API to get raw device entities.  Fix attachment point blocking code and make it appear in the REST output

minor toString fix in Device

Correct race condition in device learning and topology, remove deviceManager from listening linkEvent

This reverts commit 0ae432f4.

Conflicts:

	src/main/java/net/floodlightcontroller/devicemanager/internal/DeviceManagerImpl.java

Cleanup of topology manager to match floodlight style.  Remove StackTraceUtil.  Add packet-in listener to topology

(1) Device manager will drop packets (as the first step) if the topology indicates the packet-in port is not allowed for incoming transmissions. (2) Remove a log message from LinkDiscoveryManager. (3) Topology provides a service called isAllowed() that indicates if the port is enabled for incoming and outgoing traffic.  (4) Tests are modified accordingly.

Change device manager to not allow attachment point flapping (there was a bug in the implementation before).  Also, remove some crappy info log from ForwardingBase.

Attachment point move suppresion when moving from non-broadcast domain port to broadcast domain port wasn't working. Fixed.

Device manager will learn new attachment points only if the switch ports do not belong to the same broadcast domain.

Unit tests for the parts of device manager that should be working, and some effort at fixing compile errors in other modules