Ensuring that deferred services are set on the application before eager services are registered

After a discussion with @jasonlewis regarding service providers, we have determined that if deferred services were known to the application before the eagar loaded services were registered, they'd have access to kick-start deferred services.

This would allow you to register `$this->package()` (which relies on deferred services like `lang`) in the `register()` command, which makes a whole lot more sense than hooking onto the application's `boo()` event.

This pull request fixes issue #265 as we can now successfully register packages in the `register()` method.