slick play autosource

Hi Pascal,

So, here is my impl. As expected, it's not reactive. 

I have also added many improvements tonight. Basically, the way I was handling the json payload was very naïve. I learn how to do it properly by looking more in detail to your mongo impl.

The 'findStream' impl is the same as the 'find', because Slick does not support scrollable result sets (yet). I'm also not convinced if these a good idea. We'll need to have an open db transaction for potentially very long time.

partialUpdate is also exactly the same as update. This part can be improved. I'll have to define a kind of mapper from T to E, where T is an object that can update E. Somthing on these lines.