[Fontconfig] lcdfilter constants not recognized

[Nikos Chantziaras]

I'm using Fontconfig 2.6.0 (on Gentoo Linux).  Some applications result 
in this fontconfig error message at startup:

Fontconfig warning: "local.conf", line 11: invalid constant used : 
lcddefault

"local.conf" contains these entries:

<?xml version="1.0"?>
<!DOCTYPE fontconfig SYSTEM "fonts.dtd">
<!-- /etc/fonts/local.conf file to configure system font access -->
<fontconfig>
<match target="font">
   <edit name="autohint" mode="assign"><bool>false</bool></edit>
   <edit name="antialias" mode="assign"><bool>true</bool></edit>
   <edit name="hinting" mode="assign"><bool>true</bool></edit>
   <edit name="hintstyle" mode="assign"><const>hintslight</const></edit>
   <edit name="lcdfilter" mode="assign"><const>lcddefault</const></edit>
   <edit name="rgba" mode="assign"><const>rgb</const></edit>
</match>
</fontconfig>

I've tried all lcdfilter constants (lcdnone, lcdlegacy, lcdlight, 
lcddefault) but all of them are reported as invalid.