title: Show contextMenu on datatable left click and right click
body: <p>In the showcase of <a href="http://www.primefaces.org/showcase/ui/data/datatable/contextMenu.xhtml" rel="nofollow">datatable contextmenu</a>
  the <code>contextMenu</code> is working as normal, it shows on right click of a row, and I was wondering if it's possible to show the <code>contextMenu</code> on row select (left click) ?</p>