Renames clear_rabbit_queues and volume-usuage-audit binaries
so that they are prefixed with 'cinder-'.
As part of this change the clear_rabbit_queues binary was changed
to use dashes instead of underscores for consistency with the rest
of the cinder binaries.
Fixes LP Bug #1044386.
Change-Id: I7692a543cc67af2d342a64b84626de38c0a64f81
adding the volume notifications
added unit tests for notifications
added context for notify with rabbit
blueprint cinder-notifications
Change-Id: I5aef1e718eebb9a61e0670d524fcd5f438dee016
