Return should be completed by Event Listener

[irisSchaffer]

Instead of using if statements in a controller, this should happen in an event listener.

This will require adding an EDIT-Event to returns and listening to this event and CREATE_END (because it should be possible to complete a return in the Create decorator, when #119 is resolved).

[lsjroberts]

The whole thing needs a bit of work to use event listeners and smaller classes, so I'm gunna move this to the next milestone since it works as is.