feat(core): add more debug APIs to inspect the application form a browser

Adds `window.getAllAngularRootElements()`
Adds `ng.coreTokens.ApplicationRef`
Adds `ng.coreTokens.Ngzone`

Closes #7045
Closes #7161

modules/angular2/src/facade/lang.ts

@@ -24,6 +24,7 @@ export interface BrowserNodeGlobal {
   Zone: ZoneLikeConstructor;
   getAngularTestability: Function;
   getAllAngularTestabilities: Function;
+  getAllAngularRootElements: Function;
   frameworkStabilizers: Array<Function>;
   setTimeout: Function;
   clearTimeout: Function;