ZFSSA iSCSI vol create fails with vol type option

Vol create with volume-type option is not working since
volume_backend_name contains the class name as
predefined string. No matter what was specified in cinder.conf
as volume_backend_name, volume creation failed.
Multi-backend option and using extra specs to create custom volumes
won't work.
The fix is to look whether volume_backend_name is part of the
configuration or falls into the class name in case there is
no backend name.

Change-Id: I1bc501dd4c5689d96c7beb720b64112df1770232
Closes-Bug: 1373621
DocImpact
Handle eqlx SSH connection close on abort.

EqualLogic array CLI operation timeout causes the
SSH thread to be aborted. This would cause SSH
sessions to be orphaned and hit a max connection
limit on the array. This fix catches these aborts
and makes sure the connection is closed.

Change-Id: I9392fd5dd79eb44f252bf50217f17cc473e6f2f0
Closes-Bug: 1374613
Clarify InvalidInput exception when the size is missing

In the case where size is None, the exception message
'Volume size  must be an integer...' is misleading.

Change-Id: Ida34a84f8b3d156e3dca54de594c991b5ef73295
Merge "Handle eqlx SSH connection close on abort."
Merge "Clarify InvalidInput exception when the size is missing"
Merge "ZFSSA iSCSI vol create fails with vol type option"