Remove reset CSS code

I understand why you've put the reset.css code in `kss.css.scss`, but this can affect the elements you are building within the style guide. I had this problem with several implementations of kss-rails. 

I also removed the `//= require application` from the `kss.css.scss` file, I think this is something the user should do manually. When I use kss-rails I always include the css files in the `application.html.erb` layout. This is a little bit to automagic to my taste.. :smile: 

I hope you can merge this pull request.