Patch from Joe Orton <joe@manyfish.co.uk>:
Patch from Joe Orton <joe@manyfish.co.uk>:

Allow the environment to specify a different autoconf and autoheader.
This is useful when Expat is bundled into another program, which is
being configured using something other than the autoconf/autoheader in
the path.

tiran/expat,libexpat/libexpat,libexpat/libexpat,libexpat/libexpat,tiran/expat,tiran/expat,tiran/expat,libexpat/libexpat,libexpat/libexpat,libexpat/libexpat