applying the stack overflow hack to main library

A small hack that I created to override the derived transform based on custom requirement for this question: http://stackoverflow.com/q/18273022/853872 
and made the revisions to version 4.6.0 which is uploaded here: http://aplus1games.com/js/kinetic-v4.6.0.js
Line numbers in this file: 8031 - 8034 (very specific to image drawing)
but this patch should be applicable to all shapes