For functional testing of heat-standalone it is desirable for
heat to orchestrate on the rest of the cloud which is brought up
by devstack. This change makes the following changes to enable
this when HEAT_STANDALONE=True:
- Don't register the orchestration endpoint or create any dedicated
heat accounts
- Install and configure the heat keystone V2 auth plugin instead of
the default v3
- set heat.conf [clients_heat] url so that heat can call its own
API when no orchestration endpoint is registered
- Modify create_userrc.sh to set the required heat client env
variables to work with the standalone heat
Change-Id: Idae33bf1a9d550e2575e6390d2d7c8d3b94c401d