Fixing kss state generator js and button css tweaks

KSS provides a way to preview the states of elements.  This wasn't working.  I've fixed it by deleting the kss coffee script file and replacing it with the javscript from the following working example:
http://hughsk.io/kss-node/section-1.html
> http://hughsk.io/kss-node/public/kss.js

I've added some space between the buttons so you can see the focus state.

I've also re-added the variable for setting the button padding - and have changed the order of state declarations and order of the modifiers section.

@alexwllms @andrewtennison