VOL-3121 -  Separated out logical ports from logical agent.

Similar to flows/groups/meters.
Also modified device_route tests to generate unique port IDs (`.OfpPort.PortNo`s) across all UNI ports withing each test, i.e. within an OLT.
Also replaced logicalPortsNo map & associated NNI vs UNI logic with root device checks.

Change-Id: Ib0cecbf7d4f8d509ce7c989b9ccf697c8b0d17d6
diff --git a/VERSION b/VERSION
index 8e8299d..6cdfe8d 100644
--- a/VERSION
+++ b/VERSION
@@ -1 +1 @@
-2.4.2
+2.4.3-dev