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.
WINTERMUTE: Remove useless Rect extra argument from fadeToColor.

It is not used anywhere, and Mnemonic has confirmed that the original
engine does NOT support anything but full screen fades.
AD: Introduce ADGF_DROPPLATFORM
FULLPIPE: Drop game platform in autogenerated gameid since only Windows version existed
FULLPIPE: Fix warnings
FULLPIPE: Fix warning
RECORDER: Fix warning
SWORD25: Remove unused variable
TSAGE: Bugfixes and renaming for R2R Rim Lift interior
TSAGE: Bugfixes and renaming for R2R Rim Lift Computer
FULLPIPE: Fix function prototype
FULLPIPE: Fix logical error. CID 1086778
FULLPIPE: Remove unnecessary check. CID 1086775
FULLPIPE: Do not continue unnecessary function. CID 1086777
FULLPIPE: Fix logical error. CID 1086776
FULLPIPE: Started debug scene
TSAGE: Bugfixes for R2R Miranda interrogation
TSAGE: Fixes and renaming for R2R Spill Mountains bedroom
TSAGE: Renaming for R2R Spill Mountain throne room