Refactored ControlRenderer so that derived classes are responsible for the creation...

Refactored ControlRenderer so that derived classes are responsible for the creation of the renderer.

This allows ImageRenderer to fully manage the life cycle of the renderer, fixing the bug where changing an image in an ImageView whilsts it is on the stage also changes the cached renderer and therefore any other actor that used that cached renderer.

Change-Id: I2e8ba678445751c95c961f43da5be9a3f3cf1c58