Add todo.txt

See http://todotxt.com/.  Symlinked ~/src/dev/todotxt-cli to ~/.todo and
~/Dropbox/todo.txt.  Also pulled in
https://raw.github.com/rpdillon/todotxt.el/master/todotxt.el as an emacs
mode.  Still need to build the android app
Attempt to make menu-bar-mode work like I want

I bounce from gui to terminal emacs and only want the menu bar mode in
the gui.  This doesn't seem to work any better than what I had before,
looks like it is still only evaluated at server startup.