Add option to exclude joins from instance_get_by_uuid
Add option to exclude joins from instance_get_by_uuid

Some callers of instance_get_by_uuid do not need the data that it joins
by default.  This allows the caller the choice of getting it or not.
Specifically in this case the _sync_power_state periodic task is pulling
it unnecessarily.

Change-Id: I48cc2ea1de993b87ce6f96f4877c8d8513f507e2

n0ano/ganttclient