Implement support for multiple cameras

Right now, the Game.getCamera() is considered the only camera that can be rendered on.

We need to extend the rendering mechanism and the usages of this camera to potentially support multiple cameras.

Also, we need to be able to define a render area (Graphics2D.setClip(...)) for the camera.

• Discussion about the concept
• Implementation concept/developer notes

[KvaGram]

I think this feature is I could try giving a shot.
I just hope I am right about how your camera system works.

I would like to know a bit more about the issue though. How do you imagine it would look like in the end?

[nightm4re94]

see also #715 .