Raise InsufficientFreeMemory
Raise InsufficientFreeMemory

Kind of fixes bug 851374 & bug 858679

Raises InsufficientFreeMemory if an instance can't
start because of that. This will cause the normal
instance failure recovery to catch this problem,
set the state, and log the error. This also
removes instance_set_state from db/api.py as that
was causing these exceptions in the first place.

Change-Id: I199aa6900890531b175e28c3b93d8dfb88e135d0

citrix-openstack-build/oslo.versionedobjects,openstack/oslo.versionedobjects