Keep self and context out of error notification payload.
Keep self and context out of error notification payload.

Back in the day, having self and context in the error notifications
was handy for debugging. Now, there is a lot of confidential stuff
stored in these objects (especially when self = ComputeManager) ...
like passwords, etc.

This patch strips it out.

Also removes dead wrap_exception calls (which did nothing since they
did not specify a notifier).

Change-Id: Ieab7bd79b64e01c7bca18dbce97455e50094871c

n0ano/gantt,n0ano/gantt