docs(): fix various documentation issues

packages/ionic-angular/demos/src/searchbar/pages/page-one/page-one.ts

@@ -16,7 +16,7 @@ export class PageOne {
 
   filterItems(ev: any) {
     this.setItems();
-    let val = ev.value;
+    let val = ev.target.value;
 
     if (val && val.trim() !== '') {
       this.items = this.items.filter(function(item) {

packages/ionic-angular/src/components/loading/loading-controller.ts

@@ -47,6 +47,8 @@ import { LoadingOptions } from './loading-options';
  *
  * @usage
  * ```ts
+ * import { LoadingController } from 'ionic-angular';
+ *
  * constructor(public loadingCtrl: LoadingController) {
  *
  * }

packages/ionic-angular/src/components/menu/menu-toggle.ts

@@ -8,7 +8,7 @@ import { ViewController } from '../../navigation/view-controller';
  * @name MenuToggle
  * @description
  * The `menuToggle` directive can be placed on any button to toggle a menu open or closed.
- * If it is added to the [NavBar](../../navbar/NavBar) of a page, the button will only appear
+ * If it is added to the [NavBar](../../toolbar/Navbar) of a page, the button will only appear
  * when the page it's in is currently a root page. See the [Menu Navigation Bar Behavior](../Menu#navigation-bar-behavior)
  * docs for more information.
  *

packages/ionic-angular/src/components/virtual-scroll/virtual-scroll.ts

@@ -88,7 +88,7 @@ import { VirtualHeader } from './virtual-header';
  * ### Approximate Widths and Heights
  *
  * If the height of items in the virtual scroll are not close to the
- * default size of 40px, it is extremely important to provide an value for
+ * default size of 40px, it is extremely important to provide a value for
  * approxItemHeight height. An exact pixel-perfect size is not necessary,
  * but without an estimate the virtual scroll will not render correctly.
  *