* moved the sprite renaming out of the file system entirely into a caller-provided callback.
* renamed several functions to closer match the terms of a file system.
* moved the VM interface out of the implementation.
Due to backwards compatibility needs and for flexibility this needs to be controlled by a gameinfo setting (fullscreenautoaspect):
0: Treat all images as having an aspect ratio of 4:3, this is the default for compatibility reasons
1: Scale all images to fit the screen, i.e. either pillarbox or letterbox them.
2: Scale all images to fill the screen.
3: Scale all images so that the center 4:3 area is always fully visible. This is the recommended mode for 16:9 images designed to be shown with the sides being cropped on narrower displays.
A new DTA_ tag - DTA_FullscreenEx also exists which allows specifying the scale mode directly
Mainly done to isolate the calls that actually manipulate the global frame buffer.
V_Init alsoi initialized some palette data, which was moved to V_InitPalette and did something entirely different when running a restart as opposed to an initial start.
