*std::ofstream CPPL::ofs was added to control output format of write fnctions.
*Object types of Rows and Cols of dgsmatrix were changed.
*small modifications
*set functions were added for small_* classes.
small modification for "_" functions
tiny modification of dssmatrix::zero.
the type of Line and line object of dssmatrix were changed to std::vector.
tiny modification for streatch and expand functions
3D classes were all deleted.
*a tiny mistake on dssmatrix-misc.hpp was revised.
