It seemed that due to the way everything is called, a duplicate change broadcast here causes more problems than it could potentially solve. It is however a useful place to have something. Rather than remove it I've changed it to something that I feel best fits the naming convention you have so far. Not a huge change, but a useful one I hope.
I'm going to pull the plug on this request as I'm failing test all over the place! Going to rework this, test it locally and then submit another pull request for revised broadcasts.
It seemed that due to the way everything is called, a duplicate change broadcast here causes more problems than it could potentially solve. It is however a useful place to have something. Rather than remove it I've changed it to something that I feel best fits the naming convention you have so far. Not a huge change, but a useful one I hope.
(loving ngCart by the way, thanks for sharing it)