Bugfix in getMu(): fixed so that invalid mu guess doesn't lead to segmentation fault. Removed unused parameter p for bsplineMatrix(). Added functio bsplineVector() for computing vector of all non-zero B-splines as bspline matrix products. Bugfix in controlPolygon(): added missing reference symbol. Added function to compute bspline-coefficients of the derivative of a given spline function. Added lots of new tests