NetApp fix for vsadmin role failure for ssc

The ssc feature does not work with vserver admin
role. If the user is a vsadmin then he does cannot
use the ssc feature fully. This fix checks the access
and issues apis appropriately and also handles error
conditions.

Closes-Bug: #1253657

Change-Id: Ibc4409e5d5e6e36bba41e5f59dd94c05b87b1cde
Update hacking to hacking>=0.8.0,<0.9

Update hacking version to match version specified in requirements repo.

Fixed the following issues, which the newer version checks for:
print "" -> print("")
self.assertEquals -> self.assertEqual
self.assertNotEquals -> self.assertNotEqual

Change-Id: Ic4b70fd8f565cda28e23fe6b1da0e278f949373c
Closes-Bug: #1256738
Closes-Bug: #1256737
Closes-Bug: #1257274
All API controllers inherit from wsgi.Controller

Most of the Cinder Public API Controllers inherit from wsgi.Controller,
but still some Cinder Public APIs controllers directly inherit from
object. So it's necessary to unify all the Cinder Public API Controllers
inherit from wsgi.Controller.
1. For code cleanup.
2. When we try to do body valid check in api's put/post method later, we
can use the helper function is_valid_body instead of using try...catch
block.

Change-Id: I88812224e0b182939cfccce63982cb8f95792891
Closes-Bug: #1257198
Fixes case insensitive for resp body

Create metadata for a snapshot with key-value set, which key in uppercase
and lowercase(e.g.{"key": "v1", "KEY": "V1"), the server accept the
request and return the key-value set {"key": "v1", "KEY": "V1"}. But the
server just add one metadata because the server is not case sensitive.

The patch will modify the resp body with the one which the server added.

update_all has the same ploblem.

DocImpact
Change-Id: I684049412a4aa84f593e970c87157c74fffdfffe
Closes-Bug: #1255917
Merge "Fixes case insensitive for resp body"
Merge "All API controllers inherit from wsgi.Controller"
Merge "Update hacking to hacking>=0.8.0,<0.9"
Merge "NetApp fix for vsadmin role failure for ssc"
Fix docstring for snapshot_metadata controller

Change-Id: I8227c79c35688da03f5b850daec3215d7c79b2a6
Closes-Bug: #1258000