title: Datatables rowId starting with a number issue
body: <p>According to the Datatables specs, I can add a unique ID to every row in my table:</p>
  
  <pre><code>$('#myTable').DataTable( {
      ajax: '/api/staff',
      rowId: 'staffId'
  } );
  </code></pre>
  
  <p>However, the same spec says that IDs cannot start with a number. <code>staffId</code>in my case is a number, I tried to add some prefix to it:</p>
  
  <pre><code>$('#myTable').DataTable( {
      ajax: '/api/staff',
      rowId: 'id_' + 'staffId'
  } );
  </code></pre>
  
  <p>However, this didn't work. Any ideas?</p>