make the test file's image type configurable

This allows the image type used for testing with
the nova_test.sh script to be configured.
make compute and controller node matches regexes

This commit updates the node declarations for the
compute and control nodes so that they match on regex.

The motivation behind this is so that I can name
nodes with a unique string (timestamp) so that I can
easily rebuild compute and controller instances without
having to rebuild (or clean up) the build server.

Basically, with a single master, it is hard to re-use
cert names for two reasons:
  - puppet is not very good at reissuing certnames
  - storeconfig entries are not cleaned up (resulting in
  duplicate resources)
make usage of Cisco package repos optional.

This commit adds the variable: $::package_repo that
can be used to specify that the Cisco package repo
should be used to install the openstack packages
on Ubuntu.

The default for this value should default to cisco_repo,
but can also be set to cloud_archive to indicate the Ubuntu
upstream packages should be used.