Adds initial work in progress.
Improvements to child view layouts and VERTICAL_STACK plugin.
Adds transitionAdjust support to transition layout changes.
Adds SC.View.HORIZONTAL_STACK child layout plugin.
Adds support for modifying the childViews array and updating the child view layout.
Fixes problem when changing the paddingAfter in Vertical and Horizontal layout plugins.
Fixes problems with transitionAdjust by removing additional view state modification.