Added IComposite, IUpdatable and IDrawable

- Scene can now add any objects
- Updating and Drawing now based on IUpdatable and IDrawable
- Refactored Draw to use IDrawable
Added IDrawContext and IDrawImplementation

- Started refact/cleanup of Draw methods
- Added ICamera (read-only interface)
- IDrawContext include ICamera (remove extra param for Draw)
Added IHitTarget

- And replaced old GetHit on Layers, Sprites, DrawingElements
Replaced usage of Camera to ICamera

- When only for getting camera values