Bad exports naming for Directive/Component

[alexeagle]

the top-level 'angular2/angular2' module re-exports Component as ComponentAnnotation. The actual Component class extends Directive. However, we re-export class Directive as DirectiveAnnotation, and the re-exported Directive is just a var declaration. This breaks the angular2.d.ts since it ends up with a Component extends Directive type, where Directive is not a class.

Current workaround is to export the Directive annotation into the .d.ts, but this breaks the application because only decorators should be exposed to JS application.

[naomiblack]

@alexeagle we need to discuss how to prioritize this relative to other customer-facing issues -- might need to slip to alpha-30.

[rkirov]

The workaround is in angular2.api.ts, when this bug is fixed that file should be removed.