SCI: Disable modification of object NS rects in SCI32

This fixes the sliders in QFG4 without introducing any regressions,
as the objects are still drawn on screen using the per-frame adjusted
coordinates
SCI: Add subop 9 of kPalVary (used in SCI32, e.g. QFG4 when exiting the caves)
SCI: Add 2 workarounds for script bugs in QFG4
SCI: Add some info on kPalVary(9)/kPalVaryUnknown2
SCI: Add another workaround for a script bug in QFG4
SCI: Remove obsolete comment and code
SCI: More proper handling of scaling and global scaling in SCI32

This fixes several scaling related problems in QFG4 and SQ6
SCI: Fix the night time palette in QFG4