(reindent-then-newline-and-indent): Insert the newline
before indenting the first line.
(undo-get-state, undo-revert-to-state): New funs.
(shell-command): Don't kill the buffer even if empty.
(transpose-subr-start1, transpose-subr-start2, transpose-subr-end1)
(transpose-subr-end2): Remove.
(transpose-subr): Add `special' arg and simplify.
(transpose-subr-1): Rewrite.
(do-auto-fill): Use fill-indent-according-to-mode and fill-nobreak-p.
(rfc822-goto-eoh): Simplify.