Bug 1023664 - Calendar modularization part 1 r=millermedeiros

since it is not an static module, I would probably just use the old style:

```js
Calendar.PendingManager = (function() {
// ...
return PendingManager;
}());
```

that is closer to how things will work after the AMD conversion.. if we add the `exports` it will be very tricky to write macros to convert whole codebase and will also cause confusions.