Tighten the conditions for image sizing
Tighten the conditions for image sizing

Now that images can't be too large they also shouldn't have any
dimension that's too big. Otherwise it's easy to cause a hang. afl-fuzz
found a case of a 12 pixel wide but 17 million pixel tall image that
would then hang because threaded decode meant it had to panic every
single line.

pedrocr/rawloader,pedrocr/rawloader