title: Fabric.js: How to draw a polygon by mouse
body: <p>I want draw a <code>fabric.Polygon</code> with mouse interaction in Fabric.js.
  I made a small jsfiddle to show my actual state: <a href="http://jsfiddle.net/Kienz/ujefxh7w/" rel="noreferrer">http://jsfiddle.net/Kienz/ujefxh7w/</a></p>
  
  <p>After pressing the ESC key, the "interactive draw mode" is canceled and the polygon is finalized. But now the position of the polygon is wrong (controls are right).</p>
  
  <p>Has anyone an idea?</p>