Collect random image processing into a utility (pseudo) module; shields from presence of Image::Magick
get image sizing from LaTeXML::Util::Image and be careful about pixels, points and rescalings
get scaling from LaTeXML::Util::Image and fail gracefully if Image::Magick is needed but not found
Remove Image::Magick as a requirement; add Image::Size as a requirement
document new requirement Image::Size
fixed typo calling floatformat
note that STACKED can take 0 or more 'rows'
fixe broken registers; make \displaylines and \eqalign more forgiving; failed attempt to get eqalign to align to baseline
updated test case with added alignments