Docs for API introduced due to bluepring interface-api-cleanup.
Docs for API introduced due to bluepring interface-api-cleanup.

Change-Id: Iee2db906d154a44bbdc369f04c745e29aeb469e3

rackerlabs/melange,rackerlabs/melange,openstack-attic/melange,rackerlabs/melange,openstack-attic/melange,openstack-attic/melange