Allow passing image_ref, image_ref_alt, and network_gateway_id

Incorrect logic prevented the passing of these values.

Tests added for passing one, the other, and both pairs of each
parameter.

Conflicts:
	spec/classes/tempest_spec.rb

Change-Id: I7fe1e71f437a032f9a98c07214a1261a8001f7d8
(cherry picked from commit 735278d40804bfcf71481df54c1d3bac04b0a7a4)
Allow configuring compute tenant isolation

This configuration setting may be required for running tempest against
an existing openstack cloud.

Conflicts:
	spec/classes/tempest_spec.rb

Change-Id: I852ae3d3ab54714205c9a78fcee1506654b66efe
(cherry picked from commit 0bdf6b88e157d86012f75059bd1f6fabf8a36a73)
Fix tempest_*_id_setter to query the RAL and cache

The tempest_glance_id_setter previously would query the catalog for the
id of a glance_image resource with a given name. This doesn't work on a
split-node openstack where tempest is not on the glance host. It would
also fail horribly if glance-api.conf didn't exist.

The tempest_neutron_id_setter previously would query the instances of
neutron network IDs from the RAL once for every line in the tempest.conf
file if the network did not exist (because the cache would be nil).

Now they both query the RAL directly from the system, similar to how
tempest_neutron_id_setter did it but using Puppet::Resource.indirection,
but don't continue requerying for every line in the tempest.conf when
the given resource title doesn't yet exist, and tempest_glance_id_setter
raises a helpful error if the glance-api.conf file does not exist.

Change-Id: Icdca2c1a5f449b3fcda68d43a34452cd119303cb
(cherry picked from commit 5ef9dc94b4a395b6f60997aeed55f210acb25223)
Merge "Fix tempest_*_id_setter to query the RAL and cache" into stable/havana
Merge "Allow passing image_ref, image_ref_alt, and network_gateway_id" into stable/havana