This is a particularly ancient bug, sort of introduced by rhamph when he
optimized temp entity model handling and later exacerbated by me.
However, I suspect the actual problem is limited to nq as qw's gamedir
handling would have caused the models to be reloaded, but nq doesn't
ever change game directories once running.
While there's currently only the one still, this will allow the entities
to be multiply queued for multi-pass rendering (eg, shadows). As the
avoidance of putting an entity in the same queue more than once relies
on the entity id, all entities now come from the scene (which is stored
in cl_world in the client code for nq and qw), thus the extensive
changes in the clients.