\Phalcon\DI\Injectable no longer holds null properties of all the services in \Phalcon\DI\FactoryDefault. So long as they existed, `__get()` wouldn't be called to instantiate a new object.
Variables in the \Phalcon\DI namespace and class are now camel-cased.
Merge pull request #13 from SidRoberts/di

\Phalcon\DI can now resolve Factory Default services