I changed FcFontSetSort to respect the generic aliases better in the face

I changed FcFontSetSort to respect the generic aliases better in the face
    of language matching.
What I did was to ammend the strict sort order used by FcFontSort so that
    it 'satisfies' the language specified in the pattern by locating the
    best matching font supporting each pattern language and then ignores
    language in the remaining fonts for purposes of matching.
So, when asking for 'sans:lang=en', you'll get an English font first, and
    then the remaining fonts sorted with respect to the 'sans' alias alone
    -- pushing Kochi fonts ahead of other English-supporting Han fonts.
reviewed by: Owen Taylor <otaylor@redhat.com>