Fixes 3par driver methods that were double locking

There were many cases where the 3par drivers(FC and iSCSI) were double
locking, e.g. we were locking in the individual driver and in ‘common’.
This patch set removes all the locks in ‘common’ except the one on
‘create_cloned_volume’.

The methods ’_get_volume_state’ and ‘_copy_volume’ are only called in
‘create_cloned_volume’, so those locks were removed as well. All the other
methods in ‘common’ are only called by the driver which provide the lock,
except ‘create_volume’ which is also called by ‘create_cloned_volume’.

Change-Id: I660fbd04824bd2837e06480c8298ea5a709fc82a
Fixes: bug 1175791
Fix LHN driver to allow backend name configuration

The LHN driver wasn't allowing custom volume_backend_name to be set
via multi-backend configuration input.  In addition there were some
issues with the updating that are also addressed in this patch.

There are other drivers that are going to need updated/fixed for
this same problem, but those will be addressed in a separate patch/bug.

Fixes bug: 1173037

Change-Id: Iae247a500739d02e145511ebe96dddaff8966419
Remove old_name from kwargs when using IET helper.

The IET driver passes the input kwargs from export
directly to the IET driver, but one of the keys here
is specifically for migration and a bug associated with
going from nova-vol to cinder-uuid's.

This patch just checks in the IET code if we have the key set
and if so pops it out before passing through to iet.

Fixes bug: 1175207

Change-Id: I965bdfbe078d61b906aebc48961c1806a9fb0c59
Check that volume is at least minDisk size.

The Image service (such as Glance) provides a minDisk parameter to
indicate the minimum required disk size for the image. This change
ensures that the guidance is followed in the case of bootable
volumes.

Added unit test and fixed PEP8 issue.

Fixed issue with docstring.

Added a comment.

Fixes Bug #1175532

Change-Id: I505af53db70b5b286dbca2eaca4fc1f30a8c0b2a
Merge "Remove old_name from kwargs when using IET helper."
Merge "Fix LHN driver to allow backend name configuration"
Merge "Fixes 3par driver methods that were double locking"