Really lazy implementation for now, just draws all sprites every frame.
In the future should implement proper compositing with damage tracking.
All CG types other than QNT are removed. From what I've seen, System 4
games use QNT, PNG, AJP (encrypted JPEG) and DCF (seems to be a format
for partial CG updates). QNT is by far the most common format.
...and add OutputLog.dll stubs.
The calling convention no longer has HLL functions reaching into the
stack. The previous implementation didn't even work since the return
value could overwrite an argument that needed to be freed.
HLL libraries are compiled into the executable rather than dynamically
loaded as in early versions of System 4. These days AliceSoft does the
same thing.