edsp: optionally store a compressed copy of the last scenario

edsp: optionally store a compressed copy of the last scenario

For bugreports and co it could be handy to have the scenario and all the
settings used in it around later for inspection for EDSP like protocols.
EDSP might not be the most interesting as the user can still interrupt
the process before the solution is applied and users tend to have an
opinion on the "rightness" of a solution, so it is disabled by default.