extended so that one can optionally not process a node if its before-flow did not change
extended so that one can optionally not process a node if its before-flow did not change

xph906/SootNew,plast-lab/soot,xph906/SootNew,plast-lab/soot,xph906/SootNew,cfallin/soot,mbenz89/soot,mbenz89/soot,anddann/soot,plast-lab/soot,mbenz89/soot,anddann/soot,cfallin/soot,anddann/soot,mbenz89/soot,cfallin/soot,anddann/soot,cfallin/soot,xph906/SootNew