and fill the canvas up to the tab stop with it. once that works,
support will be added here (treating it as space.) also, fewer columns
are now generated. apparently generating a minimal number of them
fixes a bunch of the table-layout bugs.
cells on any row of the table then the very first row does not use the
cell-merging optimization; this appears to fix the last of the table
layout bugs seen in truecolor.php; also fix the foreground and
background color bugs seen in truecolor.php.