title: Extjs Charting Series with dashed line
body: <p>I am using Extjs 4 to create a line chart. Now I want to create a chart series with a dashed line. Currently my code looks the following way:</p>
  
  <pre><code>series: [{
  type: 'line',
  axis: 'left',
  xField: 'name',
  yField: 'data1',
  style: {
      fill: '#18428E',
      stroke: '#18428E',
      'stroke-width': 3
  },
  markerConfig: {
      type: 'circle',
      size: 4,
      radius: 4,
      'stroke-width': 0,
      fill: '#18428E',
      stroke: '#18428E'
  }
  }, ...    
  </code></pre>
  
  <p>I tried setting the 'border-style' to 'dashed' but this neither works. 
  Is this possible in ExtJs Charting?</p>