FEEDBACK? add option that is set for UI state changes

As I was sprinkling code around to make sure setting the `_selected` bit on books did not cause the dirty bit to be set (it was triggering another attribute to be set, causing the dirty bit) I thought of having an event `option` to quickly "ignore" certain changes. Right now I'm sprinkling in `_.isEmpty(_.omit(model.changedAttributes(), INTERNAL_ATTRIBUTES))` around.