Zone-aware versions of certain APIs: setTimeout/setInterval mostly.

Instead of waiting for zone.js to patch our global declarations and break
the lazy module loading optimizations there, we'll let it patch stuff
before "globals" gets loaded, so that it doesn't touch (and break) the code
there.

Of course, that requires that functions that need legit patching need to be
made aware of the zone, or get patched later on. The global.zonedCallback
function makes that easy, and we use it for setTimeout/setInterval.

globals/globals.ts

@@ -29,6 +29,14 @@ global.loadModule = function(name: string): any {
     }
 }
 
+global.zonedCallback = function(callback: Function): Function {
+    if (global.zone) {
+        return global.zone.bind(callback);
+    } else {
+        return callback;
+    }
+}
+
 global.registerModule("timer", () => require("timer"));
 global.registerModule("ui/dialogs", () => require("ui/dialogs"));
 global.registerModule("xhr", () => require("xhr"));