Produce .d.ts files from our typescript compilation.

Deliver them into our npm module output so users can consume them directly.

Fixes #3082

modules/angular2/src/core/util/decorators.ts

@@ -236,7 +236,7 @@ if (!(Reflect && Reflect.getMetadata)) {
   throw 'reflect-metadata shim is required when using class decorators';
 }
 
-export function makeDecorator(annotationCls, chainFn: (fn: Function) => void = null): (...args) =>
+export function makeDecorator(annotationCls, chainFn: (fn: Function) => void = null): (...args: any[]) =>
     (cls: any) => any {
   function DecoratorFactory(objOrType): (cls: any) => any {
     var annotationInstance = new (<any>annotationCls)(objOrType);