Major changes in release 1.6:
+* New macro AC_LONG_64_BITS.
+* Multiple .h files can be created.
+* AC_FIND_X looks for X files directly if it doesn't find xmkmf.
+* AC_ALLOCA defines C_ALLOCA if using alloca.c.
* --with-NAME can take a value, e.g., --with-targets=sun4,hp300bsd.
+* Unused --no-create option to configure removed.
+* autoheader doesn't change the timestamp of its output file if
+ the file didn't change.
* All macros that look for libraries now use AC_HAVE_LIBRARY.
+* config.status checks three optional environment variables to
+ modify its behavior.
* The usual bug fixes.
\f
Major changes in release 1.5: