Backward scroll

[Serg-Pogrebnyak]

Please fix backward scroll... because if I want make backward scroll for example on 2-3 cell I can do this only on one cell, I made small research and found problem
in MSCollectionViewPaging.swift
in func getNewTargetOffset(startingOffset: CGFloat, velocity: CGFloat, targetOffset: CGFloat) -> CGFloat
if I change
var offset = max(targetIndex - currentIndex, 1)
on
var offset = max(abs(targetIndex - currentIndex), 1)
all work correctly, please, check this.
Thanks a lot)