Adding vim modelines as syntax highlighting is confused by the polygot script.
First attempt at allowing of setting arguments.

I got stuck, so ended up posting on stackexchange about the question and got an
answer! You can see the post below;
http://stackoverflow.com/questions/24669373/convert-command-line-arguments-to-list-in-emacs-lisp

Setting variables to true and strings work. Setting them to integers or false
does not yet. An example of a working argument,
 ./vhdl-pretty --vhdl-upper-case-keywords