title: Angular 2 input with pipe not updating view (change detection not working)
body: <p>I have created a simple pipe which I apply to a text input.  The regex works - but something is strange.  The console log CORRECTLY shows the new value (non-alphanumeric removed), yet in the browser the input field will not update until AFTER i have type a good character.  So typing '123!!!!A' will show exclamation points until A is typed then they dissappear.  Why?</p>
  
  <p>I use the pipe like this:</p>
  
  <pre><code>&lt;input type="text" class="form-control" [ngModel]="name | inputFormat" (ngModelChange)="name=$event"&gt;
  </code></pre>
  
  <p>and the pipe is</p>
  
  <pre><code>import { Pipe, PipeTransform } from '@angular/core';
  
  @Pipe({
    name: 'inputFormat'
  })
  export class InputFormatPipe implements PipeTransform {
  
      transform(value: any): any {
      value = value.replace(/[^a-z0-9]/gi, ''); 
      console.log('new value: '+value);
      return value;
    }
  
  }
  </code></pre>
  
  <p>I suspect change detection is not working - but not sure how to fix this.</p>