Prevent reboot of rescued instance.

Do not allow rebooting an instance in the RESCUED state.  This will
revert the instance back into an ACTIVE state, which may still be
broken.  Require an explicit unrescue, instead.

Fix bug 1126163.

Change-Id: I144163666767923e3beb0a82e687066d1f3a0441
Catching InstanceNotFound exception during reboot instance

If the instance is deleted during reboot(most of soft reboot), an
InstanceNotFound exception may be raised when update instance info to DB,
and the instance may become running deleted, so catching the exception and
logging it.
This commit is a supplement of bug #1111213, which may result in the instance
becomes running deleted, when deleting an instance after soft reboot.

Change-Id: I3e8df109d431040c64e87f16ca84ff5b62dde898
Bump instance updated_at on network change.

Update add-fixed-ip and remove-fixed-ip code paths to update the
updated_at field of the instance, since from the user's perspective
through the API, they have made a change to the instance's
configuration.  In that case, it makes sense to expect that the
updated_at field gets changed.

Fix bug 1143466.

Change-Id: Icfd7d0b1b556795d94a22c1719727f8c9fc744f0
Put options in a list.

Update nova.notifications configuration options to be in a list, like
pretty much everywhere else.  For some reason when I saw this it buged
me so ... I changed it.

Change-Id: I551aba4eaceed2d1a8925e9ab621a030af83eeca
Merge "Catching InstanceNotFound exception during reboot instance"
Merge "Bump instance updated_at on network change."
Merge "Put options in a list."
Merge "Prevent reboot of rescued instance."