Extend the use of refcounted data structures for Siesta

Reference-counted data structures and containers are used sparingly in the current version. More data structure templates should be implemented to extend their use. We can make it into a library.

Distributed diagonalization on orb+k+spin for Siesta

Implementation of distributed diagonalization on orbitals+k-points+spin degrees. This will implement a new parallelization of the diagonalization routines for increase efficiency for many k-points, for example.

Check ESM model inclusion for Siesta

Implement ESM model (with accept from original authors).