x11 default option in Pango and Cairo breaks font rendering on MacOS X Leopard

[vincent <10.50%free.fr@localhost>]

Hi folks,

the default option "x11" present on pango and cairo packages does  
compile on MacOS X (Leopard), but the result is that gtk2 font display  
is broken (no glyph appears, replaced by squares).

Removing this default option solves the issue, so it might be a good  
idea to tweak the options.mk so that x11 is activated on all platforms  
but Darwin based.

Vincent