- separated the channel number from the flags in the sound interface so that the 8 channel limit can be eliminated.

- 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.

src/playsim/p_interaction.cpp

@@ -1415,7 +1415,7 @@ static int DamageMobj (AActor *target, AActor *inflictor, AActor *source, int da
 				}
 				if (P_GiveBody(source, draindmg))
 				{
-					S_Sound(source, CHAN_ITEM, "*drainhealth", 1, ATTN_NORM);
+					S_Sound(source, CHAN_ITEM, 0, "*drainhealth", 1, ATTN_NORM);
 				}
 			}
 		}