Scripts that render models in the On Object Render hook were effectively doing immediate renders in the middle of queued renders. This caused some data, such as model orientation, to 'leak' between renders. It might also have something to do with why the bug in #4637 had the particular graphical side effects that it did.
Anyway, changing the immediate renders to queued renders fixes the leaky orientations, and is probably a good upgrade for other reasons as well.
There's no need to keep all this infrastructure to run every frame for a barely used situation. This cleans it up a bit and does the position reset in the actual drawString function.
This adds an API for the scripting system which allows it to load and
display movie files using the standard movie player code which includes
multi-threaded frame decoding.
Goober5000