Added code so that we can check if the window has focus or not.
Input now depends on if the window has focus or not.
Fixed focus problem
Added support for node scaling

Added support for node scaling. Useful for when loading 3rd party
models.
Made sure that the bounding box is resized on scale
Added better comments. Added method invoked when a node is added and removed from a scene group.
Fixed some compiler warnings
Removed unused file
Moved the so called origin variable into a offset variable inside the AABB bounding box.