Implement Physics engine (1st iteration)

[seclerp]

Research result

1. Implement collision between shapes:

• Circle
• Rectangle
• Polygon, Compound Polygon
• Edge

2. Implement simple API for adding/removing colliders to the physics body
   (collider = Aether's "fixture", physics body = Aether's "body")

3. Implement game components for collider types and physics body:

• CircleColliderComponent
• RectangleColliderComponent
• PolygonColliderComponent
• EdgeColliderComponent
• PhysicsBodyComponent

4. Implement trigger IsTrigger (Aether's "IsSensor") property on colliders

5. Implement raycasting helpers over Aether's raycasting to incapsulate complex and redudant logic into simple but flexible API