AGOS: Fix sound offset table access for StS 2 Mac/Amiga.

This (hopefully) fixes bug #6549: "#6549 AGOS: Simon2 Amiga Datafiles crashes with assertion in Intro".
I don't have any copy of StS 2 Mac/Amiga thus I cannot test this.

This bug was caused by a regression in c82a75df69aa5d8f36eae52deee508ef9a61e49e.
VOYEUR: Fix a couple of hidden overloaded virtual functions
VOYEUR: Remove useless object in RL2VideoTrack
VOYEUR: Remove useless VoyeurEngine pointer in SoundManager
VOYEUR: Remove a default parameter in RL2Decoder::loadfile()
VOYEUR: Another try to get rid of the hidden overloaded functions
VOYEUR: rename audio and video track access functions
GROOVIE: Remove two useless variables
I18N: Update Hungarian translation from patch #1602
I18N: Update Czech translation from patch #1603
I18N: Update translation data file
DOC: Update Czech README from patch #1603
GIT: Ignore gettext messages.mo file
FULLPIPE: Implement sceneHandler18and19_drawRiders()
TONY: Add some missing virtual keywords
Merge pull request #446 from lordhoto/agos-offset-fix

AGOS: Fix sound offset table access for StS 2 Mac/Amiga.
TONY: Fix clang warnings - Courtesy of LordHoto
TONY: Revert 60980e783ef263f3ed5aa708dc3032779d3be923
LURE: Use the mouse pointer for menus on the Wii

Without this, this game is almost unplayable, since the
scrolling menus respond to the slightest tilt of the
Wiimote, typically scrolling from the top straight to the
bottom.  Using a mouse pointer in the menus is much easier.
FULLPIPE: Make angle arithmetics more readable in scene18/19