row's height to fit the up-popping horizontal scrollbar, but all rows
just a little, so the heights did not match. I've reworked this to not
used the ill-advised rowspan any longer, but two separate tables whose
heights match each other now in both browsers.
Also I fixed a bug in the whitespace detection code - utf8 characters
where broken into single bytes, so apparently the [:print:] character
class does not accout for them, even in //u mode, so we're selecting
the characters that we want to make visible on our own (basically
control characters lower than space, I might add more).