title: Add tooltip to legend in highcharts when hovering
body: <p>Id like to let the user know that he can remove items from the legend by simply clicking on them. To some, this may be intuitive but others may not know that they can do that. I would like to let the users know when they over the legend item that then can click to remove it.</p>
  
  <p>I am using the GWT-wrapper class for highcharts. </p>
  
  <p>Thank you.</p>