title: select2: default selection in multiple select with AJAX
body: <p>I am using the awesome <a href="http://ivaynberg.github.io/select2/" rel="noreferrer">select2</a> to create a multiple selection combo.</p>
  
  <p>I would like to programmatically select default values (as in selections the user has made previously), but I don't know how. I read that using initSelection does the trick but this is called when creating the combo and I don't want this default selection to be always done.</p>