Dell SC: Implements Replication V2

Dell SC: Implements Replication V2

This patch implements cinder Replication version 2 in the
Dell Storage Center Cinder driver.

Adds the check_result function to standardize the logging of
Dell SC Rest API errors.

Updated all todos to TODOs.

Updated all exceptions to standard formatting.  (data=msg,
reason=msg, etc.)

Added support for replicating the active replay. This is
via extra spec replication:activereplay. Replication only
replicates the most current replay. Replicating the active
replay means that the destination will be as current as
possible.

Added support for replay profiles. This is via the extra
spec storagetype:replayprofiles. Currently replication profiles
are specified by the user preferences. These can now be set
by extra spec which means by volume type.

Added release note.

Change-Id: I6e4fee07deffb9e2f86c5c514a0bcf85b37d57a1
Implements: blueprint dell-sc-replication-v2