Added missing accept_transfer to FC

The base class FibreChannelDriver was
missing the new accept_transfer method.
This was caught while running the devstack
driver certification tests again the
3PAR FC driver.
This patch adds the missing method to the
base VolumeDriver.

Change-Id: I0aa91a4f11edd03eee7607d15317b89c30732cb7
Closes-Bug: #1269633
Rename __init__.py to create_volume.py

This commit is the first step of creating packages structure for
flows. This change is required to preserve git history of renamed files
for change I63473f549f0c501fe0f373830bc1080239d01892

Change-Id: Ib5ed0e9196fa7bf4fd0b69a13c90e40c360ad8ef
Fix up calculating space info for mirrored volumes

The status reporting in the lvm driver for cinder volume incorrectly
reports free capacity. This is due to a couple of issues:
  a) the number of mirrors isn't taken into account
  b) there are some pathological cases where a
     simple division by total mirrors isn't sufficient
     because all mirrors must be on separate physical volumes.

Co-authored-by: Vishvananda Ishaya <vishvananda@gmail.com>
Co-authored-by: John Griffith <john.griffith@solidfire.com>

Closes-Bug: 1269964
Change-Id: I65e16b24367b4093a52c1c52d895fb58ef6a29ff
Remove unused method 'is_key_value_present()'

The following method is not used.
  is_key_value_present() in cinder/volume/volume_types.py

Change-Id: If1ecd22f2cfb758f0e9f7c6b730727559e9dcdf0
Add support for retype in Storwize/SVC driver

In Storwize/SVC, retype can be handled by a few cases:
1. The change may just require setting an option on the volume
2. The change may require moving the data in the same pool (e.g.,
   compression)
3. The scheduler may have chosen a different pool virtualized by the
   same Storwize or SVC, in which case we move the data as in #2

Implements: blueprint storwize-svc-retype

Change-Id: Ic2ed17bce56b5ea65e1596acfa85720cf4818fa8
Merge "Rename __init__.py to create_volume.py"
Merge "Added missing accept_transfer to FC"
Merge "Add support for retype in Storwize/SVC driver"
Merge "Remove unused method 'is_key_value_present()'"
Merge "Fix up calculating space info for mirrored volumes"