Real parameters
Created by: gcarleo
This PR addresses #176 (closed) , providing support for non-holomorphic wave-functions (and, as a special case, wave-functions with only real-valued parameters).
I also separated the SR module, taking inspiration from #150 and fixed an issue with Unsupervised example.
These changes will ease the developments associated with interfacing to pytorch in the near future.
The way I currently handle the holo/non-holo cases is fine and relatively compact, but maybe not too elegant, please suggest alternative solutions if you want!