libtoolize: migrate to new AC_CONFIG_MACRO_DIRS api.

libtoolize: migrate to new AC_CONFIG_MACRO_DIRS api.

* libtoolize.in (func_install_pkgmacro_files): Uee
AC_CONFIG_MACRO_DIRS.
(func_check_macros): Advise using AC_CONFIG_MACRO_DIRS.
(require_ac_macro_dir): Give priority to AC_CONFIG_MACRO_DIRS.
(require_macro_dir): Likewise.
* bootstrap: Give priority to AC_CONFIG_MACRO_DIRS.
* configure.ac: Define dummy AC_CONFIG_MACRO_DIRS for older
Autotools, that is allow bootstrap with current release versions.
Use AC_CONFIG_MACRO_DIRS instead of AC_CONFIG_MACRO_DIR.
* tests/testsuite.at: Source build-aux/extract-trace for access
to func_extract_trace.
(LT_AT_ACLOCAL): Use it to get the AC_CONFIG_MACRO_DIRS argument
to pass manually to aclocal for compatibility with old Automake.
Add a fallback AC_CONFIG_MACRO_DIRS definition to acinclude.m4
in the test directory.
(LT_AT_AUTORECONF): Likewise.
* tests/cdemo.at, tests/configure-iface.at, tests/darwin.at,
tests/demo.at, tests/depdemo.at, tests/early-libtool.at,
tests/libtoolize.at, tests/mdemo.at, tests/no-executables.at,
tests/nonrecursive.at, tests/old-ltdl-iface.at,
tests/recursive.at, tests/subproject.at, tests/tagdemo.at,
tests/template.at: Likewise.
* doc/libtool.texi: Update.
* NEWS: Update.

Signed-off-by: Gary V. Vaughan <gary@gnu.org>