[VOL-1825] Implemetation of the reconcile feature in the Core

This commit implements the reconcile feature in the Core as
well as the necessary changes in the GO libraries.  Changes were
also made in the simulated OLT and ONU adapters to react to a
reconcile request following an adapter restart. These changes
were tested in a 1-node deployment (1 core pair) and 3-nodes
deployment (3 core-pairs but single adapter instances).  Test
was also done using the openolt to ensure the reconcile request
does not cause panic in the Core or Openolt since the reconcile
feature is not implemented in Openolt.

Change-Id: I178d619fbcfcc6caa0ee3abfd70fc03c384c5fea
diff --git a/db/kvstore/etcdclient.go b/db/kvstore/etcdclient.go
index 4f6f90b..7f6940a 100644
--- a/db/kvstore/etcdclient.go
+++ b/db/kvstore/etcdclient.go
@@ -311,7 +311,9 @@
 
 	channelMaps := c.addChannelMap(key, channelMap)
 
-	log.Debugw("watched-channels", log.Fields{"channels": channelMaps})
+	// Changing the log field (from channelMaps) as the underlying logger cannot format the map of channels into a
+	// json format.
+	log.Debugw("watched-channels", log.Fields{"len": len(channelMaps)})
 	// Launch a go routine to listen for updates
 	go c.listenForKeyChange(channel, ch)