title: ignore pen (stylus) inputs
body: <p>Is there a was to not recognize pen inputs with hammer.js? </p>
  
  <p>I can ignore pen by checking the event type but i want them not to be recognized in the first place.</p>
  
  <p>My goal is to hold the pen on the screen and simultaneously pan or pinch per touch. The problem in here is that even if I ignore the input it won't allow/hinders further pan or pinch gestures.</p>