Move the ancient emacs 19.x port from editors/emacs to
editors/emacs19, and update the main emacs port to 21.x by copying from
editors/emacs21. Retire the editors/emacs21 port.
PR: ports/24983
As threatened on freebsd-ports: all startup scripts know about the two options
`start' and `stop' now (unless I have forgotten any). This allows us to call
the scripts from /etc/rc.shutdown with the correct option.