bug#3652: Fwd: FTBFS: nsfont.m: 'NSFontTraitsAttribute' undeclared

[Adrian Robert]

I tried to close it but the bug tracker didn't want to listen.   
Anyway, I've checked in the change to #include NSFontDescriptor.h, but  
let's leave this open now to track the fact that a workaround is  
needed for GNUstep's lack of a working

NSFontDescriptor-matchingFontDescriptorsWithMandatoryKeys:.

http://article.gmane.org/gmane.emacs.devel/113101