Pivot position is handled differently by physics- and graphics components

[Chringo]

This originates from certain models not handling these positions like the rest.
Specifically, it affects platforms since they are the ones using the models.

It has been solved for now by fetching the models OBB at different times in the code.

• In LevelState.cpp we fetch rotation data.
• In PlatformEntity.cpp we adjust the world matrix accordingly to the centre of the OBB.
  The latter happens during the update of said entity.

[Chringo]

Issue #208 might be related to this.