Add minor mode and globalized minor mode

Make this into a minor mode, so the keymap is easily customizable. Also adds group for further customization.

Btw: would you mind if I did a whitespace cleanup? (you mix tabs and space, and there's also bunch of trailing spaces). 

Also, you should probably consider using the default emacs-lisp indentation style ;) (select the whole buffer and call `indent-region`. Doing this in the early stages of developement is always better, since later it would just polute the history too much.