... eventually this is supposed to replace the old render engine/pipe/system
need brushed up Octree for queries (use current iQuadree implementation as base since it is cleaner and stable)
all mesh entities will be handled as instances inside the render engine
new iRenderEngine will be fed with entities and does nothing else then rendering
culling happens in iMeshRenderSystem based on Octree
new iRenderEngine will also be owned by a view
iView will not handle camera anymore but only provide a sub view/rect as reference for the cam in the render engine (this will be done once we remove the old render engine)
... eventually this is supposed to replace the old render engine/pipe/system