Use the varialbe to export right keystone api version

Change-Id: I1e8ea2b7173c549065ed1f08814eb4b4bb2f05cd
Fixes: Bug #1217783
Add support for Docker as Nova hypervisor

* Add basic support for hypervisor plugins in lib/nova_plugins
* Add lib/nova_plugins/hypervisor-docker to use Docker as a Nova
  hypervisor.
* Add tools/install_docker.sh to install the Docker daemon and
  registry container, download base image and import
* Configure Nova to use docker plugin
* Add docker exercise and skip unsupported ones

Nova blueprint: new-hypervisor-docker

Change-Id: I9e7065b562dce2ce853def583ab1165886612227
Move Heat to a single heat.conf

the old config files that are no longer needed (but still supported):
heat-engine.conf, heat-api.conf, heat-api-cfn.conf, heat-api-cw.conf

Change-Id: I7ba0566325539bf7215bcb606843a90b5e3e4a98
Merge "Use the varialbe to export right keystone api version"
Merge "Move Heat to a single heat.conf"
Merge "Add support for Docker as Nova hypervisor"