chore(build): Upgrade to TypeScript@1.5.3

This change also makes us compliant with 1.6.0-dev compiler,
so we can do some experiments with apps that use 1.6 features
and compile against Angular.

We should probably add a travis build for 1.6 so we stay compatible
with both versions.

modules/angular2/test/services/ruler_spec.ts

@@ -58,7 +58,7 @@ export function main() {
   });
 }
 
-@proxy
+@proxy()
 @IMPLEMENTS(ElementRef)
 class SpyElementRef extends SpyObject {
   nativeElement;
@@ -66,7 +66,7 @@ class SpyElementRef extends SpyObject {
   noSuchMethod(m) { return super.noSuchMethod(m) }
 }
 
-@proxy
+@proxy()
 @IMPLEMENTS(DomAdapter)
 class SpyDomAdapter extends SpyObject {
   constructor() { super(DomAdapter); }