tiny modification for streatch and expand functions
3D classes were all deleted.
*a tiny mistake on dssmatrix-misc.hpp was revised.
*small modification for small classes.
*modification of small matrix classes
*modification of small matrices.
*Small matrix and vector classes were added. They are so far from completion.
*data strage for dco3 and dro3 was changed.
*operator/ was added for dco3-dco3.
*bug fix for dgematrix3x3-misc.hpp
