title: select2 - do not scroll on selection
body: <p>I have a select2 dropdown, that I would like to keep open so that user can multiselect.</p>
  
  <p>The problem is, when user selects a menu item that is somewhere in the bottom, the item is selected, but the scroll position moves away.</p>
  
  <pre><code>$('#example').select2({
      placeholder: 'Select a month',
      closeOnSelect:false
  });
  </code></pre>
  
  <p>The list is big and user would search for a keyword. User should be able to select all the items containing the keyword. But now, when one item is selected, the scroll moves to the first position.</p>
  
  <p><a href="https://jsfiddle.net/3x9Lh5kt/" rel="nofollow noreferrer">https://jsfiddle.net/3x9Lh5kt/</a></p>
  
  <p>For e.g., try selecting December in the list, the scroll moves a little above, whereas I would like it to stay at the same position.</p>
  
  <p>What should be done to achieve that.</p>