[Freetype] Auto-hinter improvements

[David Turner]

Hello,

  I've just commited in the CVS some _small_ improvements to the
  auto-hinter that get rid of two annoying bugs:

      - incorrect blue zones computations, which resulted
        in some letters like a "d" appear one pixel below
        the "b". It had also strange consequences when
        rendering large glyphs, by moving certain edges
        too much

      - the composite glyph hinting has been simplified,
        and seems to give better results.


  Note that these changes are only incremental to the current
  auto-hinter module. They don't get rid of many important
  nasty artefacts (and actually bring a few new ones, the
  hardest part in fixing these bugs have been to find a
  solution that didn't distort too much otherwise correct
  glyphs :-)

  I'll later commit a complete re-implementation of the
  auto-hinter in a few weeks, which, among other things,
  will allow the support of native hints in Type 1 and
  CFF fonts..

In the meantime, enjoy and report what's wrong :-)

Regards,

- David