Add proper attributions in the Readme and in every file

[kyay10]

We use a lot of ideas from Oleg Kiselyov (who's released most things under public domain) and java-effekt and its tests. I've also been heavily inspired (and taught everything I know about continuations) by a multitude of research papers. Finally, earlier attempts at this comes from Arrow and Roman Elizarov.
This project should properly attribute all of these people. We're standing on the shoulders' of giants!