BUG: Fix missing creation of initial openflow rules upon node creation

BUG: Fix missing creation of initial openflow rules upon node creation

While using the registerDataChangeListener for createFlowCapableNodePath, we began to
see cases where onDataChanged provided no entries in getCreatedData() when it should.
To deal with that, the code will now pay attention to updates in getUpdatedData() and
treat it as create if this is the first time the listener hears about the nodeId.

Patch 2:
  - listen to operational instead of configuration mdsal tree;
  - check for create/update inside change loop
  - remove redundant [removed/added] words in log
Patch 3:
  - fix notifyNodeUpdated log
Patch 4:
  - change log level for notifyNodeUpdated
Patch 5:
  - undo patch 4. Lots of logs [1]

[1]: https://gist.github.com/67daada34dd91aff3190

Change-Id: Id1b445ec4892f9c8848b6ca5a6739948d87432c9
Signed-off-by: Flavio Fernandes <ffernand@redhat.com>