Blender Git Loki

BGE: Fix T31357: wrong zoom when sets camera.

This patch makes independant the override camera zoom and the default camera object zoom. The override zoom is 2.0f and the camera object zoom is computed with the RegionView3D camera zoom.
These features are only used for the embedded BGE, so there's no compatibility issues with the blenderplayer.
I let the override zoom with a setter to allow later to create an override camera in blenderplayer easily.

Tested with the 3 framing modes in embedded and standalone.