title: Angular 2 - Refresh ngx-datatable list issue
body: <p>I'm working on an Angular 2 project.
  I use ngx-datatable to display a list of users:</p>
  
  <pre><code>&lt;ngx-datatable class="material"
  [rows]="rows"
  [columnMode]="'force'"
  [headerHeight]="40"
  [footerHeight]="40"
  [rowHeight]="30"
  [externalPaging]="true"
  [limit]="limit"
  (select)='onSelect($event)'
  (activate)='onActivate($event)'
  [selected]="selected"
  [selectionType]="'checkbox'"&gt;
  &lt;ngx-datatable-column
      [width]="30"
      [sortable]="false"
      [canAutoResize]="false"
      [draggable]="false"
      [resizeable]="false"
      [headerCheckboxable]="true"
      [checkboxable]="true"&gt;
    &lt;/ngx-datatable-column&gt;
        &lt;ngx-datatable-column name="Name"&gt;
          &lt;ng-template let-value="value" ngx-datatable-cell-template&gt;
              &lt;div class="redNumber"&gt;{{value}}&lt;/div&gt;
          &lt;/ng-template&gt;
    &lt;/ngx-datatable-column&gt;
    &lt;ngx-datatable-column name="Title"&gt;&lt;/ngx-datatable-column&gt;
    &lt;ngx-datatable-column name="company"&gt;&lt;/ngx-datatable-column&gt;
    &lt;ngx-datatable-column name="Status" [cellClass]="getStatusClass"&gt;  
    &lt;/ngx-datatable-column&gt;
  &lt;ngx-datatable-column name="Last connexion"&gt;&lt;/ngx-datatable-column&gt;
  </code></pre>
  
  <p>When I click on the button that trigger the following showAll() method, nothing happens, unless I click a second time, the list is refreshed, or if I click once, and resize my browser's window, the list is refreshed..
  How can I refresh the list correctly? what am I doing wrong?
  In my component class, I have this:</p>
  
  <pre><code>export class M1OamRoomsListComponent{ 
      selected = [];
      public rows = [
        .... // list of users
      ];
  public limit: number;
  
  constructor(public translation: TranslationService){
      this.limit = 10;
  }
  
  getStatusClass({ row, column, value }): any {
      return {
          'disabled': value === 'Disabled',
          'enabled': value === 'Enabled'
      };
  }
  onSelect({ selected }) {
      console.log('Select Event', selected, this.selected);
  
      this.selected.splice(0, this.selected.length);
      this.selected.push(...selected);
  }
  
  onActivate(event) {
      //console.log('Activate Event', event);
  }
  showAll(): void {
      this.limit = this.rows.length;
  }
  }
  </code></pre>