[ft-devel] rewritten library detection in `configure'

[Werner LEMBERG]

I've rewritten the library detection in the `configure' script.  From
the CHANGES files (not committed yet):

    - All  libraries FreeType  depends on  are now  checked using  the
      `pkg-config' configuration files  first, followed by alternative
      methods.

    - The  new  value  `auto'  for the  various  `--with-XXX'  library
      options   (for   example   `--with-harfbuzz=auto')   makes   the
      `configure' script automatically link to the libraries it finds.
      This is now the default.

    - In case FreeType's `configure' script  can't find a library, you
      can  pass environment  variables to  circumvent pkg-config,  and
      those variables  have been  harmonized as  a consequence  of the
      changes mentioned above:

        LIBZ           -> removed; use LIBZ_CFLAGS and LIBZ_LIBS
        LIBBZ2         -> removed; use BZIP2_CFLAGS and BZIP2_LIBS
        LIBPNG_LDFLAGS -> LIBPNG_LIBS

      `./configure --help' shows all available environment variables.

    - The `freetype-config'  script now understands  option `--static'
      to emit static linking information.

Please test!  I plan to make a new FreeType release very soon and
would be glad to get some feedback.


    Werner