[Dillo-dev] patch: no size 0 images

Just a little toy to ignore images of size 0. I also tried checking for display:none, but this made css very unhappy when it reached the noncss hints code later in the function. I didn't bother to try to fit it in with the neighboring code yet, since I don't know how well this will go over. So far, a bit of browsing has mostly shown me that there is a company at scorecardresearch.com that has infected a nontrivial portion of the web. (Of course we could still dig up the same-domain code and do something with that instead.)