Multiple slide items duplicating last item

[galipmedia]

Is your feature request related to a problem? Please describe.
I think it would be better if multiple slide items didn't allow you to slide once you are viewing the last items. At present if you are viewing 3 * 4 items and your itemsToSlide is set to 4 it allows you to slide 4 times (rather than 3) and the fourth slide you see a duplicate of the 12th item.

Describe the solution you'd like
What I would like to happen is if you are viewing the last items ie (9,10,11,12) the next button should be disabled.

You can see an example on your own examples page, where the 6th item shows up on the third slide section.