- split setZero() to constructor and remove _is_initialized
- remove MPI part
- check LIS return code for each calling
- use stringstream instead of sprintf
- use INFO() instead of cout and printf for consistency

updating LisOption
- documentation
- add more solver and preconditioner type
- add matrix_type

update LisLinearSysetem
- impose prescribed values by penalty coefficient
- support matrix_type, solver_precon_arg in LisOption