NetApp check for 7 mode controller version

Queries the filer api version and raises error
if the version is unsupported.

Closes-Bug:#1223474

Conflicts:

	cinder/tests/test_netapp.py
	cinder/tests/test_netapp_nfs.py
	cinder/volume/drivers/netapp/iscsi.py
	cinder/volume/drivers/netapp/nfs.py

Change-Id: I430a41d63a2541891fdbdb20dacab9f69fa44291
(cherry picked from commit 1af8f46ea1c8e2a33ca554fa6ef3262d055c54ed)