title: Highstock addSeries to specified Y axis
body: <p>There, bizarrely, doesn't seem to be a way to target which Y axis a series is added to using the chart.addSeries() method. Nothing here (<a href="http://api.highcharts.com/highstock#Chart.addSeries%28%29" rel="nofollow">http://api.highcharts.com/highstock#Chart.addSeries%28%29</a>) about targeting axes. This results in lines destined to be plotted against the oposite axis being incorrectly plotted in the left hand one; something I would have thought to be a basic prerequisite of the method.</p>
  
  <p>Has anyone seen any hacks or plugins that might solve this or know where to go in the source to fix this?</p>