Send port status update from link discovery manager whenever a port status MODIFY message is received. Minor changes to printing of link discovery updates and addition of some trace logs.

Update attachmentpoint whenever topologyChanged() notification is received.  It is not necessary to process every event; just one update call per topologyChanged() should take care of fixing all attachment point changes.

Updates to attachment point learning and udpating.  DeviceManager listens to topologyChanged() events.  Whenever a port goes down or a switch is removed, attachment points are updated.  Cleanup of link discovery manager updates; cleanup also includes port up/down switch update/removed messages.

portEnabled(short) should return false if a port is not present.  TopologyManager checks for "Special" ports and port status as part of "isAttachmentPointPort".  The checking of this logic in devicemanager is remoed.

Rewrite of attachment point logic.  Attachmetn points are maintained independent of entities.  Update test cases.  Duplicate Mac test is disabled for the time being.

During flow reconciliation, device manager should not call learnDeviceByEntity, which would incorrectly update timestamps of entities existing in flow cache. It should call findDeviceByEntity instead.

If we cannot find an entity in the primary index we need to
classify it into an IEntityClass and the search in the class index.

* Fixed couple of bugs in Device.getIPv4Addresses().
* Add more debugging output to DeviceManagerImpl

* implement findDestDeviveByEntity()
* findDevice() and findDestDevice() will now throw an exception of the
  supplied fields are not sufficient for the lookup
* test and comment polishing
* reorganizing testing code

[BSC-1838]

[BSC-1838]

* IEntityClassifier only returns a single entity class per entity and all
  entities of a device must belong to the same entity class. Semantics for
  multiple classes was unclear.

* IEntityClassifier is now an IFloodlightService to have a cleaner way of
  setting the classifier to use (the classifier needs to be set before
  DeviceManager.startUp() is called).

[BSC-1838]

2 - Fixed an issue in DeviceManagerImpl where it was sending updates with the old device.

Update to attachment point flapping logic.  Use active time instead of last seen to order the entities.  Corresponding changes to unit tests.