SCUMM: Implement original AD AdLib output.

This implements the original AD output and enables it for Indy3 and Loom DOS.
It is not enabled for Monkey Island DOS because it would break multi MIDI
support. However, there are also drawbacks for Indy3. In the catacombs
we were able to play sfx (Indy walking around) and the background music
at once. This was not supported in the original player and thus also does
not work with this reimplementation.

This fixes bug #2027877 "INDY3: Non-Looping Sound Effects".
This fixes bug #1159581 "ADLIB: Adlib Emulation doesn't Respect Volume Settings"
for Indy3 and Loom.
I18N: Move specification of engine specific files to enginedir/POTFILES.

This allows to keep the engines to specfiy the files for translation close to
the engine sources itself.

Thanks to criezy for his suggestion on this approach.
AGOS: Use strncpy() instead of strcpy(). CID 1003679, 1003681
SCI: Give more verbose error messages on arithmetic errors
SCI: Fix several script bugs in Hoyle 4 (Bridge)

This also fixes bug #3361925 - "SCI: HOYLE4: Crash in bridge"
TINSEL: Add the English Mac version of DW1 (bug #3614864)
AGOS: Use Common::strlcpy() instead of strncpy()

As suggested by LordHoto.
AGOS: Simplify string parsing
AGOS: Use Common::String for savegame filenames
AGOS: Add two savegame-related FIXMEs
TIZEN: Silence cppcheck warning in scanStringUntil()

This is consistent with scanString(), and I have verified that the
included test cases still work.
WINTERMUTE: Fix warning
TSAGE: Fixed playing of scanner tones when switching between characters
TSAGE: Corrected usage of quinn and speaker classes across scenes
TSAGE: Clean up of R2R scene 1550 player position tracking
TSAGE: Variable renaming in R2R scene 1550
TSAGE: Further R2R scene 1550 fields renaming
TSAGE: Further R2R scene 1550 renaming, and fixing tracking junk state
TSAGE: Added code to make newly added inventory items immediately visible
TSAGE: Fix cursor when leaving the scanner dialog