ZVISION: Rename _halveDelay to _doubleFPS, to match its config setting
ZVISION: Move some event/rendering code out of the main engine code
ZVISION: Fix a warning
ZVISION: Move more graphics code out of the main engine code
ZVISION: Implement auto-saving
ZVISION: Correct the script names of the location-specific cheats
ZVISION: Remove duplicate blitting code for images and animations
ZVISION: Remove duplicate image loading code
ZVISION: Remove duplicate subtitle code
ZVISION: Turn off subtitles, if requested
ZVISION: Add an FPS timer (accessible with F10, or the "FRAME" cheat)
ZVISION: Quit with an error message dialog if no font files are found
ZVISION: Delete the render manager after the script manager on quit

This is necessary, as the script manager may include references to the
render manager, such as side effects in Zork: Nemesis. Fixes a crash on
engine exit when the current scene contains such effects
CREDITS: Update the credits for the ZVISION engine
SCI: Fix warning
ZVISION: Clean up the game settings
ZVISION: Add some advanced engine features, and document the engine
ACCESS: Rewrite sound queueing (WIP)
ZVISION: Add support for disabling animations while turning

Also, clean up and document game configuration options, and add a TODO
for QSound support
ZVISION: Remove dead code (uint is always > 0)