[VOL-1862] rwCore waits for Kafka and KV Store

This commit consists of the following:
1) Make the rw_core wait for kafka and KV Store to be up before
proceeding with its processing.  Previously, rw_core would have
bailed out if kafka/KV was not available. The number of retries
(default=-1, i.e retry forever) and retry interval are both
configurable.

2) Remove a non-json printable variable from the debug log in the
model.

Change-Id: I8d1ef90bf5d202a6f8ae59610aa780292b2844ce
diff --git a/db/kvstore/consulclient.go b/db/kvstore/consulclient.go
index 4b25b5f..c4fa0af 100644
--- a/db/kvstore/consulclient.go
+++ b/db/kvstore/consulclient.go
@@ -63,6 +63,12 @@
 	return &ConsulClient{consul: consul, doneCh: &doneCh, watchedChannelsContext: wChannelsContext, keyReservations: reservations}, nil
 }
 
+// IsConnectionUp returns whether the connection to the Consul KV store is up
+func (c *ConsulClient) IsConnectionUp(timeout int) bool {
+	log.Error("Unimplemented function")
+	return false
+}
+
 // List returns an array of key-value pairs with key as a prefix.  Timeout defines how long the function will
 // wait for a response
 func (c *ConsulClient) List(key string, timeout int, lock ...bool) (map[string]*KVPair, error) {