title: ng2-completer get selectedObject
body: <p>How can I get originalObject in selected event?</p>
  
  <p>for example in this code I want use value field but search in colors!</p>
  
  <pre><code>protected searchData = [
  { color: 'red', value: '#f00' },
  { color: 'green', value: '#0f0' },
  { color: 'blue', value: '#00f' },
  { color: 'cyan', value: '#0ff' },
  { color: 'magenta', value: '#f0f' },
  { color: 'yellow', value: '#ff0' },
  { color: 'black', value: '#0' }
  ];
  
  constructor(private completerService: CompleterService) {
    this.dataService = completerService.local(this.searchData, 'color','color');
  }
  </code></pre>
  
  <p>and this is my template:</p>
  
  <pre><code>&lt;ng2-completer [(ngModel)]="searchStr" [datasource]="dataService" 
  [minSearchLength]="0"&gt;
  </code></pre>
  
  <p>Thanks.</p>