Fix for fonts with broken kerning tables

[Just van Rossum]

Folks,

A client of mine ran into a problem with FT1.x kerning: for some fonts that
*do* have a format 0 kerning table there still seemed to be no kerning. The
problem turned out to be easy & stupid: the kern table in the font wasn't
sorted, so the binary search didn't work.

Obviously, the font is broken, but since those fonts are "out there" I
believe a fix to FT is a Good Thing. And it doesn't need to cost much: I
can quickly check whether the table is sorted, and only qsort the table if
it isn't. This will happen in Subtable_Load_0().

Would anyone object to such a fix? I might check it in this weekend, but if
there are strong objections I can take it out again. (And if it's ok, I'll
also adapt the fix for FT2.)

Thanks,

Just