dot/emacs: Various Emacs-server hacks.

  * Start up server on Emacs 23 regardless of whether there's a window
    system.

  * Start up the Emacs server as well, because it's actually pretty
    good.  And it's better on Emacs 23.

  * Protect the individual server-start operations with `trap's so that
    either can fail without preventing the other one from starting.