Schedule the link discovery task on startup.

Various UI changes (https://github.com/floodlight/floodlight/pull/245)

Remove invalid attachments before sending it for comparison in attachment point update logic.

Increase CONSISTENT_TIMEOUT to 30 seconds in attachment point maintenance. (https://github.com/floodlight/floodlight/pull/247)

Send port status changed update from link discovery upon port status MODIFY message.  Minor changes to printing of link discovery updates and addition of trace logs.

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.

A few other small formatting cleanups.

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. (https://github.com/floodlight/floodlight/pull/244)

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.

 	Don't hard-depend on topology for unit tests and fix warnings (https://github.com/floodlight/floodlight/pull/243)

Fix a failing unit test.  Manual merge.

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 por

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.

Move initialization of topology instance from startUp() to init(). (https://github.com/floodlight/floodlight/pull/240)

Topology Manager must create new topology instance upon startup. (https://github.com/floodlight/floodlight/pull/239)

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 removed.

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 in device manager.  Attachment points are maintained independent of entities.

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

Remove methods that change static IEntityClass variable (https://github.com/floodlight/floodlight/pull/235)

fix null pointer exception (https://github.com/floodlight/floodlight/pull/234)

Fixes for BSC-2134 and BSC-2148 (https://github.com/floodlight/floodlight/pull/233)