Replace mkinstalldirs with `install-sh -d', as automake recommends.

Replace mkinstalldirs with `install-sh -d', as automake recommends.

* Makefile.in (mkdir): Use `install-sh -d' instead of mkinstalldirs.
(sync-from-gnulib): Don't sync mkinstalldirs.

* make-dist: Don't distribute mkinstalldirs.

* leim/Makefile.in (install): Use `install-sh -d' rather than mkinstalldirs.

* lib-src/Makefile.in ($(DESTDIR)${archlibdir}):
Use `install-sh -d' rather than mkinstalldirs.

* configure.in, doc/emacs/Makefile.in: Update comments.

* admin/notes/copyright: Remove mkinstalldirs.