Topic/operators

The remaining tests have succeeded, I'm quite confident now that this implementation is a good choice.
Actually, it might be better not yet to add an sclang interface for floats, as there is still a possibility that one would want to implement a version based on the rationals - which is perfectly possible. For the ugen version it seemed to me that rationals would be a little over done, and mostly one would truncate the inputs anyhow.