- 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.
- A_BossDeath relies upon this function in particular.
- This completes CheckReplacee's purpose, allowing for varied actors to count as one particular actor, such as a Fatso for map07 and avoid lowering the walls until they are all dead.
Many had leftover non-default constructors/ assignment operators, and some were initialized, even though the initialized data was never used.
In case of FCycler this even caused a default setting to be overwritten when used inside FDynamicLight.
