OldestParticle was not properly tracked which could result in circular lists.
To make maintenance easier, the replacement code and the free particle part were merged into one to only have one place where the linked list is modified.
* remove duplicated fields
* make native functions use direct calls
* remove unnecessary pointer from particle_t
* create HWSprite directly in Construct
- Effectively similar to Actors, but without the excess.
- Can be created with either the `level` function or the static `Spawn` function in ZSprite.
- STAT_SPRITE belongs to ZSprites only; ZSprites cannot be moved out of, nor can anything else be moved in to, this statnum.
Misc:
- Fixed (Sprite)Offset taking roll into account.
Crediting phantombeta, RicardoLuis0 and RaveYard for assistance.
Due to C++ conversion rules this was a bit too volatile. There's really not enough places where being able to pass a string directly into the sound API was beneficial - the two most frequent functions now got overloaded variants.
- 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.
This was only run on a state change and missed every external light change.
Any place which wants to flag a light change now only will set a flag and at the end of the thinker loop all flagged actors will be processed.
For performance reasons this was merged with the P_RunEffects iterator loop.
