application: Expose grilo as an application property
Do not instanciate Grilo object in its own file. Grilo should be initialized as soon as possible because Window and Views need to know at startup if the tracker plugin is available. So, moving it to Application makes sense. Move Grilo to Application, and make it a property so that it can be accessed as application.props.player. It is a readable property, since there is no reason to change it.