Refactoring & new animations #61, #62, #63

I constantly have to adapt the Entity and Actor classes and their respective states, because when I started coding the game engine I haven't taken into account that there would even be states.

I have also commissioned new idle animations.
Instead of having a character idle only facing the screen, I have decided that they should idle randomly (up, left, right, down).

Remember idle animations for soldiers in RedAlert2?

Full video logs: