Code cleanup and bug fixes
Sum: orderOfSubContoursDict -> contourOrderingByValue, added plotting code, added function CN.GetContourPoints, added SubContourTools to __init__.py

orderOfSubContoursDict (+/- indexes) is converted to contourOrderingByValue (tuples of (index,direction))
I can't overstate that this makes the code much simpler (who'd 've thunk it?) as well as working correctly...

Added a new "plot" function for SubContour and "scPlot" & "cellPlot" for CellNetwork

Added "SubContourTools" as a module to load in the __init__.py