Some packaging tweaks (https://github.com/bigswitch/bigswitchcontroller/pull/3329)

Conflicts:
	bigfloodlight/src/main/resources/apps/bigtap.json

  1. Moving debug event for switch connect/disconnect to Controller (from LinkDiscovery) to be consistent with Shudong's changes
  2. Bug fix in OFChannelHandler that was causing NPE
  3. Bug fix in DebugEvents that was ignoring flushNow directive in event registry
  4. Updated unit test

Conflicts:
	floodlight/src/main/java/net/floodlightcontroller/linkdiscovery/internal/LinkDiscoveryManager.java

* Make all fields final or volatile
* Still not 100% safe (visibility): lastSeenTimestamp of the entities
  can be changed unsynchronized

 	Fix warnings  (https://github.com/bigswitch/bigswitchcontroller/pull/3312)

Includes framework for creating events and managing memory for events via
thread local stores and global circular buffers per registered event.
Also includes a basic rest api call to retrieve event history.
Unit tests have been added

* make sure we do things in the right order (setting role, sending role reqs)
* fix getName() in HAListener's
* transition AddressSpaceManager before DeviceManager to Master
* flush counters from threads
* add trace logging and more counters

Fix NPE in deleteLinks() during keysModified() on Slave Node (https://github.com/bigswitch/bigswitchcontroller/pull/3307)

Debug Counters related to SyncStore for BigLinkDiscovery (https://github.com/bigswitch/bigswitchcontroller/pull/3287)

moved json property declaration to variable decalartion

also remove custom serializers for switch, port variables

Fix possible sending ofsyncvalue messages without any values (https://github.com/bigswitch/bigswitchcontroller/pull/3286)

Updates to link discovery based on switch state and notification changes. (https://github.com/bigswitch/bigswitchcontroller/pull/3285)