feat(typings): add typing specs

add test in gulpfile which will compile a basic TS file with generated
angular2.d.ts to ensure generated d.ts is valid syntactic TS

Adds support for enums in .d.ts generation pipeline.
Removes renaming reexports in http module.

typing_spec/basic_spec.ts

@@ -0,0 +1,18 @@
+///<reference path="../dist/docs/angular2.d.ts"/>
+
+import {Component, bootstrap, View} from 'angular2/angular2'
+
+@Component({
+  selector: 'my-app'
+})
+@View({
+	template: '<h1>Hello {{ name }}</h1>'
+})
+// Component controller
+class MyAppComponent {
+  name: string;
+
+  constructor() { this.name = 'Alice'; }
+}
+
+bootstrap(MyAppComponent);