(Hungry WS Deletion): Rename c-hungry-backspace to

(Hungry WS Deletion): Rename c-hungry-backspace to
c-hungry-delete-backwards, at the request of RMS.  Leave the old name as
an alias.
(Movement Commands): Correct the definition of c-beginning-of-defun, to include the
function header within the defun.
(Comment Commands): State that C-u M-; kills any existing comment.
(Electric Keys): Add a justification for electric indentation.
(Hungry WS Deletion): Clear up the names and complications of the
BACKSPACE and DELETE keys.
Correct two typos.