Fix "Could not set video mode"
When LÖVE can't set the correct video mode, it silently rolls over and dies.
Not very good, considering this could happen in a correctly written game, simply because some gamer didn't have a fancy enough graphics card or whatever.
FSAA is the worst offender.
Possible solution: check before setting video mode. If it doesn't work, do the sensible thing and pick the closest one (and auto-disable FSAA, in many cases).