New design for class InitState. Big improvement since it allows setting all sites in constructor and doesn't require typing site number variable twice (constant source of errors).
Updated sample/sandbox DMRG codes to again allow changing spin representation with only a single line of code.
Changed InitState const reference to model_ to a pointer to allow copying InitState objects. Added setAll method as well.
Turned orthogonalize() back on in MPS addition algorithm.
Updated all unit tests to compile with latest library.
Reimplemented MatrixRef VectorRef mult using dgemv_.