Watson <pwatson@redlinepy.com>.
* builds/unix/configure.ac: Renamed to...
* builds/unix/configure.raw: This which now serves (with appropriate
modifications) as a template for configure.ac.
* version.sed: New script.
* autogen.sh: Generate configure.ac from configure.raw, using
FREETYPE_MAJOR, FREETYPE_MINOR, and FREETYPE_PATCH from freetype.h.