High Resolution Gigahertz and Terahertz Spectroscopy and Theory of Parity Violation and Tunneling for 1,2-dithiine (C4H4S2) as a Candidate for Measuring Parity Violating Energy Difference between Enantiomers of Chiral Molecules (SCS Fall Meeting, University of Berne, 21.8.2017-22.8.2017)