Bug Fix to Bind Renderable's ElementOfRenderable to it at real time
- Why bug happens
    - If we have two Renderables share the same IA or Shader, the Scene will call Renderable's setIA or setShader at the Load time twice, then the later Renderable's IA will overwrite the previous pointer to Renderable
- How to Fix
    - remove bind when setIA, setMesh, etc
    - add new function called BindElementOfRenderableToMe() which will bind its all ElementOfRenderables to itself
    - call BindElementOfRenderableToMe() at each call to Init(), Draw(), Destory(), that is bind at Real-Time