topology keeps a list of applied link updates. topologyAware modules can query updated links after getting topologyChanged event

DeviceManager update to take into account that previous attachment belongs to non-broadcast domain attachment point.
Adding an interface to ITopologyService that indicates if tunnels are enabled for traffic between two hosts.

Controller now needs to listen for storage notifcation and it will
dispatch updates if the controller node IPs change.

We now have three different types of updates in the Controller.updates
queue ==> Refactored to use different update classes that implement a
common IUpdate interface instead of a several types and a switch
statemet.

Add unit test for Controller.updates queue

Retab that caused some unrelated chagnes but now now more tabs:
    flconext, addInfoProvider, removeInfoProviderm getControllerInfo

Retab also causes changes in flcontext: that's only indentation.

Needed to touch quite some files to refactoring: rename
IHARoleListener -> IHAListener

[#29035681]

2 - Update module HA role change actions
3 - Add unit tests for HA role changes

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

Now we will at least get an error message when an Exception occurs
instead of silently killing the thread.
[Forgot to add all files to commit]

Introduce a convenience method inSameIsland, which is the same as inSameCluster.  In future, they may have different functionalities.

Introduce a method called isConsistent(..) that compares an old attachment and a new attachment point. If the new attachment point is not consistent with the old one, then it has to be learnt by the device manager.

Device manager should implement ITopologyListener to clear out attachment points when topology changes.

(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.

Needed to move threadpool reference into startup()
was in init()

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

New TopologyManager.  Previous TopologyImpl would simply do link discovery.  Cosmetic refactoring (renaming etc.) would be done separately.