Remove libvirt legacy LVM code

The Change-Id Ib36b962971fd1f66ea9a0818e91fec59e118e686 fixed an
issue which could have caused volumes no longer being able to be
cleaned up due to it's reliance on the instance_name_template
configuration option.

There was code in place to handle both disk formats which are
the legacy format (volume name prefixed by instance name) and
the new one (volume name prefixed by instance uuid).

This commit removes the legacy format which was due to be
removed from the code.

UpgradeImpact - this removes support for really old lvm names that
could have been created in Havana clouds. That means there is a
possible failure to cleanup of lvm volumes that existed uniterupted
since Havana.

Change-Id: I28497a650fbd012643080951f7d86ab8780fd59c
Add missing instance action record for start of live migration

We should add action record for live migration as we did for resize,
start,etc.

Change-Id: I6838727bf51f4bcdba0010c72bd2d5132bcf2cc3
fix usage of obj_reset_changes() call in flavor

There is a bug where obj_reset_changes() isn't being called with a
list, resulting in a no-op (changes to 'projects' not reset).

Change-Id: Iea14195a55d855bfa2cfc096260cf960e911b219
Merge "fix usage of obj_reset_changes() call in flavor"
Merge "Add missing instance action record for start of live migration"
Merge "Remove libvirt legacy LVM code"