Initialized event loses context

[Chreekar]

After updating froala-editor and angular-froala to 3.0.6 from 2.9.3 the events no longer pass the editor instance as a parameter to the callback, instead it is bound to this. This is no problem except for the "initialized" event where this is bound to window instead of the editor instance. The effect is that you cannot access the editor instance from the initialized callback.

[Chreekar]

I solved it by modifying the directive according to my comment in #214