CPPLapack Code

*just added some comments.

*to_dsymatrix etc. were added.

*implicit cast constructors (constructor from dgbmatrix to dgematrix, from zhematrix to zgematrix, and so on) were deleted.
*to_dgematrix and to_zgematrix member functions were added.

*zgsmatrix and zhsmatrix were added.

*halfway development of dssmatrix

dssmatrix was renamed to dgsmatrix.
(zgsmatrix is under construction.)

modification to get rid of forbidden codes
*added nullify function for all smart-temporary classes
*put nullify() at the end of shallow_copy functions and shallow copy constructors
*modified destroy function to assign NULL to all pointers

Row and Col were added in dssmatrix for faster search of (i,j) component

The trunk cpplapack source code was added.