Consideration: use plinkx to set prompt

From the following URLs:

- http://comments.gmane.org/gmane.emacs.tramp/7839
- http://www.reddit.com/r/emacs/comments/15am20/configing_emacs_tramp_with_putty/

Might just see how connecting to this box using plinkx works, and see if
I can just set the variables there myself or something.