Cleans up power_off and power_on semantics
Cleans up power_off and power_on semantics

compute.api changes:
  * improves state handling for delete/restrore
  * removes hack to deal with SHUTOFF on start
  * fixes api tests (volume shouldn't detach on stop)

compute.manager changes:
  * uses power_off/power_on for stop/start

virt.libvirt changes:
  * implements power_off/power_on for libvirt
  * synchronizes usage of domain.create()
  * cleans up usage of instance.name
  * added tests for power_on and power_off
  * fixes bug 1006950

Change-Id: I91845a643e3f97955e7c81ca57c6ee5aa0a3d295

n0ano/ganttclient