BT-168 - process all flow-mod failure cases and cleanup the policy that has this flow that failed to be pushed.
BT-169 - set xid in default flow-mods in the bigtap flow cache.
BSC-3361 - suppress spurious warning syslog when switch sends barrier-reply, as it is unhandled. - changes to src/main/java/net/floodlightcontroller/core/internal/Controller.java

OF Cluster from a L3 NOF domain.
o VRS detects traffic destined to TEP's MAC and !TEP IP and applies the
  virtual routing logic to the device corresponding to dstIp. It marks the orig dst device
  in the floodlight context
o Forwarding checks for the orig dst device in floodlight ctxt being a TunnelEndPoint.
  If so, it ensures that the packet is received on the designated port for the TEP device and
  computes the route to the destination device as follows:
      o Intra Cluster SourceSwitch --> DestSwitch
      o Prepend {Source Switch,Port}
      o Append {Dest Switch,Port}
o Reconcile changes in VRS and Forwarding to handle such flows.
o Junit tests

removing unused imports in ControllerTest

Change buildRoute() to use only RouteId as the only parameter as srcId and dstId are included in it.

BT-143 and BT-144 : Fixed a corner case bug in qualifying a policy for duplication-free-path, even if the policy has only one delivery port, if criteria for using duplication-free path is satisfied, then compute a duplication-free path [BT-143]. Introduced a barrier between clean-all-flows and subsequent flow-mod install messages to ensure reliable clean up of flow-table [BT-144].

- When computing uptimes and start times use the information provided by the JVM.

Conflicts:
	floodlight/src/main/java/net/floodlightcontroller/core/internal/Controller.java

from null to non-null as device moved

[BSC-3247] DeviceManager must learn devices correctly when the ethernet destination MAC in an ARP response is different from sender hardware address.  A device corresponding to the sender hardware address and sender protocol address needs to be learned.  Update unit tests accordingly.

[BVS-324] Remove the usage of getAPMap() when retrieving attachmentpoints.  Its use is needed only when computing duplicates.

findbugs stuff (https://github.com/bigswitch/bigswitchcontroller/pull/2616)

NodePortTuple class implements comparable to allow for sorting of nodeport tuples. The sorting is first based on the switch id and then on the port id.