title: How to format a number in template?
body: <p>Since the Angular 2 documentation is really poor, I have a question:</p>
  
  <p>I have a number:</p>
  
  <p><code>{{ -1739034 | percent : '1.2-2'}}</code> and it is displayed as :  <code>-1,739,034</code>.</p>
  
  <p>How can I transform it into  <code>-1'739'034</code>?</p>
  
  <p>Thanks!</p>