Added clamp01_coord to ijkcoord.txx.
Cleaned up code.
Moved compute_isosurface_grid_edge_intersection to sharpiso_intersect.cxx.
Removed files not used in grad2hermite.
Corrected error in compute_isosurface_grid_edge_intersection.
Error created major errors in grad2hermite.cxx.
Replaced intersect_isosurface_grid_edge_sharp3D with
compute_isosurface_grid_edge_intersection.