title: how to make rounded corners on polygon with kineticjs
body: <p>I am using <code>kineticjs</code> to do some HTML5 graphics, and I would like to make a rounded corner on a polygon. How can I do this? At the moment I have this polygon:</p>
  
  <pre><code>var poly = new Kinetic.Polygon({
              points: [50, 100, 180, 100, 180, 120, 200, 120, 200, 180, 50, 180, 50, 100],
              fill: '#00D2FF',
              stroke: 'black',
              strokeWidth: 1
          });
  </code></pre>
  
  <p>Please note that I want the lower left corner to be a rounded corner with a radius of 10. How can I do that?</p>