LayoutTraits: made ConstraintProperty's totalSize listener self-contained
LayoutTraits: made ConstraintProperty's totalSize listener self-contained

mdittmer/foam,mdittmer/foam,osric-the-knight/foam,jlhughes/foam,jlhughes/foam,osric-the-knight/foam,mdittmer/foam,jlhughes/foam,osric-the-knight/foam,foam-framework/foam,jacksonic/foam,jacksonic/foam,jacksonic/foam,foam-framework/foam,osric-the-knight/foam,foam-framework/foam,jacksonic/foam,foam-framework/foam,jlhughes/foam,mdittmer/foam,foam-framework/foam