* configure.in (AUTOMAKE): Create m4/amversion.m4.

* configure.in (AUTOMAKE): Create m4/amversion.m4.
* m4/amversion.in: New file.
* m4/Makefile.am (m4data_DATA, EXTRA_DIST): Replace by ...
(dist_m4data_DATA): ... this.
(nodist_m4data_DATA, DISTCLEANFILES): Add amversion.m4.
* m4/init.m4 (AM_INIT_AUTOMAKE): Require
AM_SET_CURRENT_AUTOMAKE_VERSION.
* automake.in (seen_automake_version): New variable.
(scan_autoconf_traces, scan_one_autoconf_file,
scan_autoconf_files): Scan for AM_AUTOMAKE_VERSION and complain
when the version used in aclocal.m4 differs from Automake's.
* tests/defs (ACLOCAL): Look in ../m4 too.
* tests/installsh.test (ACLOCAL): Likewise.
* tests/installdir.test (installdirs-local): Run $ACLOCAL.