Stop keeping info/dir in the repository.

Stop keeping info/dir in the repository.

* build-aux/dir_top: Move here from admin/.

* build-aux/make-info-dir: New script.

* Makefile.in (bootstrap-clean): Delete info/.
(info-dir, ${srcdir}/info/dir): New rules.
(info): Also make info-dir.
(check-info): Rename from check-info-dir.
Instead of info/dir entries, check @dircategory in info/*.info.

* make-dist: Use `info' rule rather than `info-real'.
No more info/COPYING (not even the right license for info/ files).

* info/: Remove from repository.

* admin/update_autogen (info_dir):
Use dir_top from build-aux/ rather than admin/.

* .bzrignore: Ignore info/ altogether.

* doc/emacs/Makefile.in: Comment.