Remove the autogen/ directory

Remove the autogen/ directory

Ref: http://lists.gnu.org/archive/html/emacs-devel/2013-10/msg00806.html

* autogen: Remove directory.  Move update_autogen to admin/.
* autogen.sh: Remove reference to copy_autogen.
* GNUmakefile (configure):
* Makefile.in (bootstrap): Do not try to run copy_autogen.
* config.bat: Use msdos/autogen rather than autogen.

* admin/update_autogen: Move here from ../autogen.
(usage): Update.  Remove -l, add -A.
(autogendir): New variable.
(ldefs_flag): Default to set.
(genfiles): Reduce to only ms-dos relevant files.
(main): Make checking autogen sources optional.
Make copying of autogen files optional.

* msdos/autogen/config.in:
* msdos/autogen/Makefile.in: Move here from ../autogen.

* nt/INSTALL: Remove reference to copy_autogen.

* nt/config.nt: Comment.