Apply Docu Restructuring and Update

[SebastianSemper]

1. Each class now has its own rst file
2. changed all copyright years to 2018 (little late though)
3. Added list of publications to Index
4. Removed some clutter
5. changed theme to something nicer and more standard
6. Added new Inverse matrices preemtively
7. made scipy interface more prominent

I think we can readily merge it as it is and reopen a new pull request for the more elaborate changes to the documentation. this way we can get these simple but nice changes out the door sooner.

So how exactly do we deploy our docu? I have no idea. I think we did some readthedocs stuff automatically.