Move hard coded values out to asset files

[Delwin9999]

There's a lot of hard coded values in the code base. Most of these are intended to be variable but there's no real way to set them (I.E. gravity). Pull all of these out to some sort of configuration file.

[bonesoul]

EngineConfiguration should be a good point for moving them. Though actually the Player logic should be completely moved out of the Engine project to sample Game project.