Reset of caption padding correction

Patch (in addition to the previous) to save some more improvements before implementing an easier way to assure the caption always has the same width as the image. See http://stackoverflow.com/questions/6593425/best-method-to-fit-a-child-di....

Patch (in addition to the #4 patch) to get rid of the caption correction completely. Solved with CSS only.

To check if we can eliminate unused $width and or $height variables in the code. Needs furthermore extensive testing.

A commit candidate.