3PAR with pool-aware-cinder-scheduler

HP 3PAR support for the pool-aware scheduler.
Adds support for a list of CPGs (pools).  Uses
model update when our volume-type CPG is used
instead of the scheduler selected CPG.

In cinder.conf, hp3par_cpg now accepts a list of CPGs.

DocImpact
Implements: blueprint pool-aware-cinder-scheduler-hp3par
Change-Id: I74ef0af5390311eb1a529e0d5d4875c4f7d04156
Merge "3PAR with pool-aware-cinder-scheduler"