CPPLapack Code

*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.

*bug fix on dsymatrix::set function. Thanks, Hui Li!!
*change the return object type of zero,initialize,and set functions
to enable quick initialization like ...
const dgematrix A(dgematrix(3,3).zero().set(1,1,x));

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

The trunk cpplapack source code was added.