The Rotational Zeeman Effect of Imines II. Cis- and Trans-Ethanimine and Trans-Syn- and Trans-Anti-Propenimine, their g-Tensors, Magnetic Susceptibility Anisotropics, Molecular Electric Quadrupole Moments, 14N Nuclear Quadrupole Coupling Constants, and 14N Spin-Rotation Coupling Constants; a Microwave Spectroscopic Study Combined with Quantum Chemical Calculations