Adding redistancing Sussmann

src/level_set/redistancing_Sussman/ComputeGradient.hpp

src/level_set/redistancing_Sussman/GaussFilter.hpp

src/level_set/redistancing_Sussman/HelpFunctions.hpp

src/level_set/redistancing_Sussman/HelpFunctionsForGrid.hpp

src/level_set/redistancing_Sussman/NarrowBand.hpp

src/level_set/redistancing_Sussman/RedistancingSussman.hpp