* Ely: GamePhysicsManager: started to add collision notification.
* Ely: GamePhysicsManager: collision notification completed. TODO: test.
* TODO: Config component to be added for overall game configuration.
* Ely: added GameConfig component: to be implemented.
Merge branch 'master' into notify-collisions
Merge branch 'master' into notify-collisions
Merge branch 'master' into notify-collisions
* Ely: written some docs.
* Ely: continuing to implement GameConfig component.
* Ely: GameConfig component construction completed.
* Ely: notify collision events tested successfully.
* Ely: some corrections.