NetApp NFS: Do not reference dst_img_local before assignment

This patch moves the assignment of the dst_img_local variable to before the
try/finally block that references it so that the finally block will have this
variable no matter where in the try block an error is raised.

Change-Id: Iab48b46559f18a3d6b044abe4bc3e615e7fee075
Closes-Bug: 1309047
Handle volumes no longer existing in resume delete

init_host resumes deletes for volumes with a status of 'deleting'. It
does these sequentially, and sometimes a volume could be deleted under
it, causing a bad stacktrace. This will gracefully handle those
situations and move on. Added coverage for resume volume delete being
successful as well.

Change-Id: I5b30265609b65804f2da77d9daa84b640de7939c
Closes-Bug: #1322340
3PAR volume detach with host in a host set

When deleting the last VLUN for a host, try to
delete the host.  If the host is in a host set
this will fail.  When that happens, log a nice
message including the reason, but don't fail
or hang the delete VLUN.  Leave hosts in host
sets.

Closes-Bug: #1317134

Change-Id: Ie3f8f94c05a6a318de866598f9e9c4c5d84926f4
Merge "NetApp NFS: Do not reference dst_img_local before assignment"
Merge "3PAR volume detach with host in a host set"
Merge "Handle volumes no longer existing in resume delete"