Add test for specific known good chdk firmware version about spreads

[jbaiter]

That should be no problem, I'm already doing something of that kind to check for remote shooting capabilities.
The question remains how we would define "known good", I only have two cameras and while a certain revision might work perfectly fine with my setup, I'd like to get at least a few other experiences with the same combination as well.
I think the A2200 would be a good candidate for that, given that you shipped a lot of kits with it, so there should be a reasonable pool of experience to draw from.