More tests and more test data

[mfherbst]

We really should add more tests and check more properties after an SCF run.

More properties

• Orbital energies
• Energy terms
• Orbital coefficients (more problematic, since unitary rotations wrt. a reference can occur)

More test cases

• O in a larger basis (cc-pvdz, some Coulomb Sturmian basis) as ROHF and UHF
• H2O in (cc-pvdz, UHF and RHF)
• H2 near bond breaking (RHF and UHF with spin broken)

The test data should not be stored in this repository, we better use a separate one or a webserver.