- disentagled C++ and Lua parts: Sound effect data is transfered to C++ on startup,
no lua requests during runtime for sound events anymore.
- added user sound set support
- moved damping code from world.cc to sound.cc
- moved lots of sound option menu code from OptionsMenu.cc to sound.cc
- moved not-oxyd-related parts of sound set initialisation from oxyd.cc to sound.cc
- damping additionally depends on sound effect name
- write "silence string" to command line when a non-existing sound is
requested by lua (needed for "Acoustic Memory" when using incomplete user
sound sets)
- silent sound set (deactivated by default)
Todo:
- rename data/sound to data/soundsets
- move default sounds to data/soundsets/enigma (?)
- documentation in reference manual
- sound priorities
- correctly coalesce sounds with different volumes
