Emacs: Add Meta bindings.
Emacs: Enable dired-find-alternate-file.
Emacs: Remap <return> and ^ in Dired.

These suggestions come from Xah Lee:
http://ergoemacs.org/emacs/emacs_dired_tips.html
Emacs: Require Dired.

This is required (heh) for the previous commit to work.
Emacs: Remap 'q' in Dired to use kill-this-buffer.