Add a script show all possible state transitions

The output of this script will be useful in documenting all possible
state transitions.

Change-Id: I24e442ce20fe7730c915a77b85014f44075e03fd
Do not assume nova provides a fault on ERROR

A nova server object in an ERROR state does not
always provide a fault attribute to get the error
reason from.

Fixes bug: #1213285

Change-Id: I861951207cf8fd526a65f768154c76afd0be9081
Merge "Add a script show all possible state transitions"
Merge "Do not assume nova provides a fault on ERROR"