creating instances failed as a result of regression in last commit

creating instances failed as a result of regression in last commit

The previous commit to the tree organizes resource names by
stack.resource.  Most of the openstack APIs take resource ids
but the instance create operation requires text identifiers.

Rewrite the text identifiers for the nova security groups before
starting an instance.

Change-Id: I8a842868781ecb353f66b5a4e3d022766a4c8a0e
Signed-off-by: Steven Dake <sdake@redhat.com>