Provide atomic database access nvp plugin

* This patch ensures that if multiple queries are done against the
  database they are atomic.
* Removes outdated doc string comments.
* Changes update_network so that it doesn't update the network name in nvp
  since the name is retreved from the database.
* Fixes get_network to return the correct status from nvp. Previously,
  it was always returning ACTIVE.
Fixes bug 1097990

Change-Id: Ie3eb67c98dcb36b18cbef2e0905b59eba48ca81d
Merge "Provide atomic database access nvp plugin"