GRAPHICS: Update the root node in Renderable::getSize()

No idea why, but this is now necssary, otherwise getSize() sometimes
won't take the scale into account... -.-
GRAPHICS: Don't modify the scene blending for non-transparent materials

Yeah, on second thought, that won't work.
NWN: Add back Creature::lastChangedGUIDisplay()
NWN: Add back the ingame GUI
KOTOR TESTCASE