- added Marisa Kirisame's CHAN_OVERLAP flag.
- exported S_IsActorPlayingSomething to ZScript.
The sound API change required deprecating A_PlaySound and S_Sound. There are now new variants S_StartSound and A_StartSound which have two distinct parameters for channel and flags.
# Conflicts:
# src/bbannouncer.cpp
# src/fragglescript/t_func.cpp
# src/g_shared/a_lightning.cpp
# src/p_effect.cpp
# src/p_mobj.cpp
# src/p_switch.cpp
# src/playsim/p_spec.cpp
# src/sound/s_doomsound.cpp
# src/sound/s_doomsound.h
# wadsrc/static/zscript/base.zs
# Conflicts:
# src/intermission/intermission.cpp
# src/sound/s_doomsound.cpp
