kangax/fabric.js — pull request #857 by briefbanane (2013-09-18 21:52:07+00:00)
Title: Allow toggling of flipX/Y to flip the whole group

This will add a function toggle to the group class, which will redirect everything to its children. Moreover it will change the positions of the objects (mirror them respective to the group center) when flipX or flipY is the given property.