Carousel BEFORE_CHANGE fires in confusing situations

[angusm]

The BEFORE_CHANGE event fires when a new transitionTarget is assigned.

This is confusing when the transitionTarget matches the currently active slide.

transitionTarget can be assigned matching the currently active slide to support situations where a draggable slide has been moved a bit, but not enough to change the active slide, and it needs to transition back to center.

The naming of BEFORE_CHANGE in this circumstance is confusing. It is probably worth splitting this into two events BEFORE_CHANGE and BEFORE_TRANSITION, firing one or both as necessary. This would also apply to AFTER events.