connector/edid probing races

Talk to Jonas (jadahl) on irc, he had 3 mutters running and on hotplug all 3 of them were diving into the connector getting code. Now I think we can avoid this in userspace by not probing when not owning the VT, but it's still messy behaviour.

It looks like one thread does a getconnector, this fills out the EDID blob with a specific blob id, then second thread does getconnector, which replaces the EDID blob with another one the first thread calls get property blob, but the blob id it is looking for is destroyed.

Ideas? Dave.