Family only has one 'i'.

[David Chisnall]

Hi Everyone,

I just spent a little while trying to work out why some of my code  
didn't compile with GNUstep, even though it looked like everything it  
needed was implemented.  It turns out that GNUstep declares  
NSFontFamiliyClassMask instead of NSFontFamilyClassMask in  
NSFontDescriptor.h.

David