Put version information into the configure script.  Reported by Paul
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.
diff --git a/version.sed b/version.sed
new file mode 100644
index 0000000..c281ff5
--- /dev/null
+++ b/version.sed
@@ -0,0 +1,5 @@
+#! /usr/bin/sed -nf
+
+s/^#define  *FREETYPE_MAJOR  *\([^ ][^ ]*\).*$/freetype_major="\1" ;/p
+s/^#define  *FREETYPE_MINOR  *\([^ ][^ ]*\).*$/freetype_minor=".\1" ;/p
+s/^#define  *FREETYPE_PATCH  *\([^ ][^ ]*\).*$/freetype_patch=".\1" ;/p