Torch implementation

[aklawonn]

The main new feature here is the pyro-solver (based on Torch). But also some other things have been added during the development, like for example the post-processing or the general noise model.

[atulag0711]

Just as a side note:

1. I didnt implement plate notations yet. That insures conditional independence which might be necessary.
2. I think this is currently cpu Torch in use. At one point, needs to be converted to GPU version to leverage the full computational capabilities.