fix: declare var global.

This is required as otherwise our code ends up
with an undeclared symbol in `global`. It declares
it to the same type as it'd have in nodejs, <any>.

modules/angular2/globals.d.ts

@@ -29,3 +29,5 @@ interface BrowserNodeGlobal {
   setInterval: Function;
   clearInterval: Function;
 }
+
+declare var global: any;