Use bool for Emacs Lisp booleans.

Use bool for Emacs Lisp booleans.

This is more natural, and on my platform (GCC 4.7.1 x86-64) it
makes Emacs's text size .03% smaller and presumably a bit faster.
* admin/merge-gnulib (GNULIB_MODULES): Add stdbool.  This documents a
new direct dependency; stdbool was already being used indirectly
via other gnulib modules.
* lib-src/make-docfile.c (enum global_type): Sort values roughly in
decreasing alignment, except put functions last.
(compare_globals): Use this new property of enum global_type.
(write_globals): Use bool, not int, for booleans.
* src/lisp.h: Include <stdbool.h>.
(struct Lisp_Boolfwd, defvar_bool):
* src/lread.c (defvar_bool): Use bool, not int, for Lisp booleans.
* src/regex.c [!emacs]: Include <stdbool.h>.
(false, true): Remove; <stdbool.h> does this for us now.