[devel]  Moved libpng-config.in and libpng.pc-configure.in out of the scripts

    directory, to libpng-config.in and libpng-pc.in, respectively, and
    modified Makefile.am and configure.ac accordingly.  Now "configure"
    needs nothing from the "scripts" directory.
  Also, avoid redefining PNG_CONST in pngconf.h
diff --git a/configure.ac b/configure.ac
index f947187..30fbea0 100644
--- a/configure.ac
+++ b/configure.ac
@@ -117,8 +117,8 @@
 AC_SUBST([binconfigs])
 
 # Config files, substituting as above
-AC_CONFIG_FILES([Makefile libpng.pc:scripts/libpng.pc-configure.in])
-AC_CONFIG_FILES([libpng-config:scripts/libpng-config.in],
+AC_CONFIG_FILES([Makefile libpng.pc:libpng-pc.in])
+AC_CONFIG_FILES([libpng-config:libpng-config.in],
 		[chmod +x libpng-config])
 
 AC_OUTPUT