Carried over bug fixes from function_derivative_matrix to Derivative_matrix::operator* and Derivative_matrix::inverse
Carried over bug fixes from function_derivative_matrix to Derivative_matrix::operator* and Derivative_matrix::inverse


git-svn-id: 4705079bc6b8aadf675e3696f5c015a6aa4916e3@3779 3c1deb5b-d424-0410-962d-aba41a686d42

hsorby/zinc,hsorby/zinc,hsorby/zinc,OpenCMISS/zinc,OpenCMISS/zinc,OpenCMISS/zinc,hsorby/zinc,OpenCMISS/zinc