(demo app) Application menu bar enhancements (#2123)

* remove MDL from app component

- new app menu bar based on angular/material

* fix app selector

* improve menu bar labels

demo-shell-ng2/app/app.component.ts

@@ -28,7 +28,7 @@ import {
 declare var document: any;
 
 @Component({
-    selector: 'alfresco-app',
+    selector: 'adf-app',
     templateUrl: './app.component.html',
     styleUrls: ['./app.component.css']
 })
@@ -93,9 +93,4 @@ export class AppComponent {
             this.settingsService.setProviders(this.storage.getItem(`providers`));
         }
     }
-
-    onDragOverMainPage(event: any): boolean {
-        event.preventDefault();
-        return false;
-    }
 }