Move all model properties from properties.hh to model.hh, delete properties.hh

Model only includes the properties and has the model documentation now. We can simply copy the properties into the model since model is what the user wants to include in the problem. Then the TypeTag that is used is directly visible there.

Once !656 (merged) and !661 (merged) are merged, the following models still need to be adapted:

Edited Dec 21, 2017 by Timo Koch