* lib/Automake/XFile.pm: Update to use ChannelDefs.

* lib/Automake/XFile.pm: Update to use ChannelDefs.
(close): Call Automake::FileUtils::handle_exec_errors on errors.
* automake.in (scan_autoconf_files): Exit with $?=63 on version
mismatch.
(scan_autoconf_traces): Likewise.  Close the autoconf pipe to
capture abnormal exits.
* aclocal.in ($exit_status): Remove, and use Channels.pm's $exit_code
instead.
(trace_used_macros): Close the autom4te pipe to capture abnormal exits.
* lib/missing: When a tool has run and exited with $?=63, emulate
it.  Adjust the diagnostic and pretend the tool is tool old in this
case.  Use an emacs-updated "scriptversion" variable.
* configure.in: Output tests/aclocal-${APIVERSION} and
tests/automake-${APIVERSION}.
* tests/aclocal.in, tests/automake.in,
tests/missing.test, tests/missing2.test: New files.
* tests/defs.in (AUTOMAKE, ACLOCAL, PATH): Define
to use tests/aclocal-$APIVERSION and tests/automake-$APIVERSION.
* tests/dup3.test: Remove. alocal9.test, acloca10.test, and others are
already testing for this.
* tests/depacl2.test, tests/dup2.test, tests/order.test: Fix
configure.in so that aclocal works.
* tests/defun.test: Quote the AC_DEFUN body.
* tests/Makefile.am (TESTS): Add missing.test and missing2.test,
and remove dup3.test.
(check_SCRIPTS): Add aclocal and automake.