SCI: Revert "Add a hack to fix bug #3596335"

This reverts commit f019d5a4881c8ee42fa36ef0613d9e82b3b36297.
SCI: Revert "Properly fix bugs #3267956 and #3605377"

This reverts commit 17ca8d14b1e0d1960485029878c728ef4d6d6132,
except for a minor unrelated change to the workaround for bug #3605269

Conflicts:
	engines/sci/sound/soundcmd.cpp
SCI: Revert "Fix script bug #3555404 - "SCI: KQ6 Spider Scene Game Freeze""

This reverts commit 8524ebd699254a6786033f0e41b9a45c563feb11.
SCI: Revert "Clarify comment from rev 5654e12 further"

This reverts commit 9f74a6eda2355bb09b9b963be41509ed67016a6c.
SCI: Revert "Added a more specific workaround for bug #3267956.[...]"

This reverts commit 5654e1257551bf176c7fd06c756612bec3d79033.

Conflicts:
	engines/sci/sound/soundcmd.cpp