Entity (1)

[PtrMan]

A step toward Component based design.

Advantages:

• drawing and logic are seperated (so we can run simulations without visualization)
• behaviours are customizable and don't depend on the remaining functionality of the entity
• ideally we need just one logic for rendering and simulation of different applications

[patham9]

I like the idea of Behavior being seperately from drawing. But why did you create a runtime-string-dispatched makeEntity method instead of just using the constructors?
Can you separate this into 2 PR's? The behavior one I would have accepted for sure.