configury: move autoconf macros to build-aux subdirectory.

* ltdl/m4: Move from here...
* build-aux/m4: ...to here.
* configure.ac (AC_CONFIG_MACRO_DIR): Adjust.
* Makefile.am (config_macro_dir, ACLOCAL_AMFLAGS): Adjust.
* build-aux/m4/gnulib-cache.m4: Regenerate.

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