Publish correct gpfs attributes to cinder.conf

Three extra attributes were being published to cinder.conf when volume_driver
was set to gpfs.  This patch corrects this problem.

Closes-Bug: #1320372
Change-Id: I4e1290aeac92c56beaad0ebd0941afaf249469e2
Add support for misc options in cinder.conf

Add misc_cinder in cinder.conf like misc_nova.
Add test
Closes-Bug: #1314105
Change-Id: Ia23809e33dd1b64e276d373ce87355dbecf857e9
Make retrieval of vmware_host_pass optional

Before this change, a non-vmware user would (without developer mode)
have to create a data bag item for this pass even when not using it,
because otherwise the get_secret's call would fail.

Plus, it's more in line with the other drivers.

Implements: blueprint vmware-password-databag
Change-Id: I48a6e23d6aa9abd106e65e70b40662c8d4cca5fc
Adapt Strainerfile to gate jobs

For easier testing before committing a change to review, it'd be nicer
to have the Strainer tests in line with what happens on openstack-infra.

Change-Id: Ie025ebd300632af39090d5b180cf9f09e775c237
Fix default value for storwize_svc_vol_rsize

The default for storwize_svc_vol_rsize is '2%', should be just 2.

Change-Id: Ief51ad89bceaee043279e03b57c09c2b3f59d0af
Closes-Bug: #1320647
Merge "Make retrieval of vmware_host_pass optional"
Merge "Fix default value for storwize_svc_vol_rsize"