Fix which dependency is injected w/ current elem.

Docs for the "Injecting a directive from the current element" indicate that having a dependency of `dependency: Dependency` should cause the current element's dependency to be injected, but then uses the ID value from the parent element in the example.

Closes #1032

modules/angular2/src/core/annotations/annotations.js

@@ -139,7 +139,7 @@ import {Injectable} from 'angular2/di';
  * @Decorator({ selector: '[my-directive]' })
  * class MyDirective {
  *   constructor(dependency: Dependency) {
- *     expect(dependency.id).toEqual(2);
+ *     expect(dependency.id).toEqual(3);
  *   }
  * }
  * ```