fontconfig font cache included in recent Xenocara snaphots

Hi,

In the recent snapshots for i386, amd64 and may be other arches
xbase42.tg now includes a copy of /var/cache/fontconfig, the font cache
managed by fontconfig.

The goal of this change is to avoid the (quite long) rebuild of the font
cache when the fonts themselve are updated (by installing xfont42.tgz),
which is noticeable in xdm's startup time, not that xdm uses
fontconfig/Xft fonts.

If someone encounters problems with this, or still sees long font-cache
rebuilds after upgrading to a snapshot, please report it to me.
-- 
Matthieu Herrb