title: Angular: Formatting numbers with commas
body: <p>Title very much sums up my needs. </p>
  
  <pre><code>123456789 =&gt; 123,456,789
  12345 =&gt; 12,345
  </code></pre>
  
  <p>What's the best way to get this conversion ? Don't suggest currency pipe in Angular-2 as I don't need $ or currency symbol to be prepend to my output.</p>