Fix amazon provisioning by hiding cloud quota

Currently, only Openstack has the notion of cloud quota.  However, the view that
decided whether or not to show cloud quota during provisioning based the
decision on whether or not the current workflow was a cloud workflow.

The decision needs to be more fine grained for now.  Instead of only checking
for a cloud workflow, the view now checks specifically for an openstack
workflow.

https://bugzilla.redhat.com/show_bug.cgi?id=1127459
Fix tenant column on pre_prov partial

In cases where both amazon and openstack images are available in the "Select and
Image" table in the _pre_prov partial, the table shows up with uneven rows.
This is caused by amazon not having tenants whereas openstack does have tenants.

Originally, the logic for showing the table column header would arbitrarily
include the header based solely on the first template in the list to be shown.
Now, the column header is shown if any of the templates in the list can show a
cloud tenant.

Also, the logic for showing the table cell is based on whether the table tenants
header is shown.

Additionally, the logic for showing the data inside the table cell is based on
whether the template in the current column can respond_to the `cloud_tenant`
method.

https://bugzilla.redhat.com/show_bug.cgi?id=1127459
Merge pull request #365 from blomquisg/bz1127459-amazon-provisioning

Bz1127459 amazon provisioning