* there is now a more clear distinction between camera_2d and camera_3d functions in the engine code
* simplified camera2d's exported interface - now everything happens directly with the 'current' variable and make_current and clear_current are no longer exposed- there were some situations where calling one instead of set_current would result in incomplete results
* rebased to current godot master
- verdog
879f84d8f8
- Note that i did not rename the original Camera related methods.
