SWORD1: Improve speech endianess detection in mac version

Because of the way the speech is compressed with duplicate samples
being stored with a negative size and a single value, when reading the
data with the wrong endianess we can end up with a lot of duplicate
samples which biased the result with the way the old heuristic was
coded. Hopefully this change to skip duplicate samples will make it
more robust.
MADS: Fix starting TextView palette setup and scroll ending
MADS: Fix exiting the game
MADS: Fix OPL init error when showing credits multiple times
MADS: Fix custom color setup for quotes display
MADS: Fix text not properly being erased when showing quotes
CGE2: Update English autodetection.
MADS: Fix spare screen background changes for TextView showing quotes
CGE2: Make the intro skippable.
MADS: Properly free menu items when main menu is freed
MADS: Fix palette for difficulty selection dialog
KYRA (LOL): Fix bug #6727 due to incorrect assertion range.

This was the bug with "Engine assertion at various dialogues if no items
in inventory".
Revert "CGE2: Make the intro skippable."

This reverts commit 5e099e90bcdfb87c289b919ddac60e60fbf6bdd7.
There's no need for this addition, since the intro was skippable before that too, by hitting the ESC key.
See System::touch().
AMIGAOS: Make use of the new drawer icon

On AmigaOS the user can customize every icon including drawers.

This is a customized drawer icon for ScummVM with the original "S"
scaled on top of it.

This icon may change with further revisions of AmigaOS4 (if the
default icon images change).