Changed Hamiltonian generator logic, very small change.
Hamiltonian generation uses sparse matrices now. Solver uses an expm_multiply() routine which should be better than expm() as it directly calculates the action of expm() onto Psi.
Cleaning up solver.py a little.
Added new problem for benchmarking. It simply constructs random alpha and beta coefficients between 1 and -1. The command line arg -k or --simtype is used to feed in the qubit number.
Testing everything else with new sparse matrix organization of simulation. Eigensolvers, other plotting and data output work now. Ready to merge to master branch.