title: highcharts vs highstocks - compatible?
body: <p>I have a number of sites using highcharts and have a licence.
  However, I've now been asked to implement 'flags' which are only available in highstocks.</p>
  
  <p>So, if I 'upgrade' to highstocks, will my sites with highcharts continue working as before ?</p>
  
  <p>Or, is there a workaround to create flags in highcharts ?</p>