Torch distributions rewrite.

[srush]

From conversations with @justinchiu

The current distributions framework need a bit of an overhaul. We think this is an area with a lot of potential, so we are thinking through the constructors and use cases.

[srush]

Mostly done with #88

[Ricocotam]

Hi,
May I suggest adding some documentations on the distribution module ?

Or could you give some hints on how it works so I could do it ? I tried to use it but there's no documentation and the code isn't easy to understand.

[srush]

Yeah, there will be a writeup with clear description, but it is still being worked out.

[Ricocotam]

Alright, may I help ?