[Fontconfig] fontconfig not recognizing Luxi Mono as monospace

[Alan Coopersmith]

One of the fonts X.Org distributes is "Luxi Mono", aka luximr.ttf
from either:
  http://cgit.freedesktop.org/xorg/font/bh-ttf/tree/
or:
  http://xorg.freedesktop.org/releases/individual/font/font-bh-ttf-1.0.1.tar.bz2

One of our users complained that he couldn't get xterm to accept this
font with:  xterm -fa "LuxiMono-10" - it always chose the bold version
instead of the regular, since xterm specifies that it needs a monospaced
font, but fontconfig thinks only the bold font is monospaced and the
roman version is not.