devstack+contrail works on ubuntu

devstack+contrail works on ubuntu, single host.  The API server starts.  I can create networks, boot VMs, and ssh into them.

updated latest version of repo url
install distribute before other python libs
added reset_config=True to api_server.conf
don't start cassandra at boot, just by stack.sh
handle python package install paths with pywhere
make a fake contrail-version when contrail isn't installed by yum