chore: kill ListWrapper.create() and .push().

These wrappers are not natively understood by
ts2dart. Removing them will improve Dart2JS
compilation due to fewer megamorphic calls to List
functions.

It also makes Angular code more succinct and
improves type safety in Angular due to better type
inference of the Array component type.

This change exposed several bugs in Angular.

modules/angular2/src/mock/browser_location_mock.ts

@@ -10,7 +10,7 @@ export class DummyBrowserLocation extends SpyObject {
   internalBaseHref: string = '/';
   internalPath: string = '/';
   internalTitle: string = '';
-  urlChanges: List<string> = ListWrapper.create();
+  urlChanges: List<string> = [];
   _subject: EventEmitter = new EventEmitter();
   constructor() { super(); }
 
@@ -28,7 +28,7 @@ export class DummyBrowserLocation extends SpyObject {
   pushState(ctx: any, title: string, url: string): void {
     this.internalTitle = title;
     this.internalPath = url;
-    ListWrapper.push(this.urlChanges, url);
+    this.urlChanges.push(url);
   }
 
   forward(): void { throw new BaseException('Not implemented yet!'); }

modules/angular2/src/mock/location_mock.ts

@@ -17,7 +17,7 @@ export class SpyLocation extends SpyObject {
   constructor() {
     super();
     this._path = '/';
-    this.urlChanges = ListWrapper.create();
+    this.urlChanges = [];
     this._subject = new EventEmitter();
     this._baseHref = '';
   }
@@ -38,7 +38,7 @@ export class SpyLocation extends SpyObject {
       return;
     }
     this._path = url;
-    ListWrapper.push(this.urlChanges, url);
+    this.urlChanges.push(url);
   }
 
   forward() {