[9fans] font height.

[erik quanstrom <quanstro@coraid.com>]

code2000 and cyberbit both have accented characters that are
taller than the nominal height of the font, like Ó.  unfortunately
the draw library, the frame library, rio and acme are not aware that
different characters in a font may have different heights.  thus characters
like Ó are chopped off at the knees.  fonts like pelm solve this by 
compressing the height of accented caps, an unattractive but effective
solution.

the obvious place to start in helping libdraw understand different
letter heights would be in in libdraw/stringwidth.c.  the function 
_stringnwidth, should be replaced with _stringnsize, returning a Point.

but that's the easy part!  rio and acme have fine-tuned drawing routines
that make the assumption that fonts are fixed-height.

- erik