* Makefile.am (do_subst): Fix the substitution of @configure_input@.
(automake, aclocal): Create the output atomically and make it
read-only, as done in the Autoconf package.
* lib/Automake/Makefile.am (do_subst): Fix the substitution of
@configure_input@.
(Config.pm): Create the output atomically and make it read-only.
* m4/Makefile.am ($(top_srcdir)/m4/amversion.m4): Substitute
@configure_input@ and make the output read-only.
* lib/Automake/Config.in, m4/amversion.in, tests/aclocal.in,
tests/automake.in, tests/defs.in: Add a @configure_input@ line.
* lib/Automake/Config.in: New file.
* lib/Automake/Makefile.am (nodist_perllib_DATA, do_subst,
CLEANFILES): New variables.
(Config.pm): New rule.
* Makefile.am (maintainer-check): Adjust expected differences
between automake.in and automake.
* aclocal.in, automake.in: Use Automake::Config.