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)

Conflicts:
	floodlight/src/main/resources/floodlightdefault.properties

Change topologyChanged() method signature to provide an unmodifiable list of applied updates during the method call.

Still needs more work:
 * we don't generate updates if a stored switch has changed yet
 * we don't deal with (unlikely) change of port name <-> number

BVS known devices for sync and small change for SwitchPort (https://github.com/bigswitch/bigswitchcontroller/pull/3271)

flow reconcile engine - cleanup and minor fixes (https://github.com/bigswitch/bigswitchcontroller/pull/3270)

it pretty much was immutable already but it wasn't explicit since
members weren't private final. Now they are.

Add event to signal when all switches have reconnected after failover.  (https://github.com/bigswitch/bigswitchcontroller/pull/3268)

add default constructor for LinkInfo
add JsonIgnore annotation for getLinkType as it does not correspond to an actual class variable

Fix Helium bug in switch state machine. More controller.java unit tests (https://github.com/bigswitch/bigswitchcontroller/pull/3254)

Add event to signal when all switches have reconnected after failover

Also add more resilience to consolidateStore.

* Fix switch state-machine bug. Need to set the state before calling
  sendRoleReqest because sendRoleRequest could directly set the role
  to Master if the switch is known to not support Nicira role requests
* In REST handling: replace empty roleChangeDescription with none so we
  don't violate IFloodlightProvider.setRole's contract of requiring a
  non-null description
* Use correct package name for FloodightProvider in
  bigfloodlight.properties