.emacs: remove reformat-hard-wrap

I haven't used it in too long
.emacs: remove gnus configuration

It is an artifact.
.elisp/revive.el, .emacs: retire revive
..emacs: advertise [(control shift backspace)]

I hope to use it.
.emacs: retire org-mode but for beamer integration
.emacs: move to new-style keybinding specs