Remove Lua function SetAmmoStore
This function very obscure and has never been used, nobody will miss it.
See
issue #145 for full rationale.
Lua callback: onUsedAmmo, after using up an ammo
Useful to know when e.g. shotgun attack has finished
Syntax: onUsedAmmo(ammoType)
* ammoType: Ammo type of used ammo
Note: Not called for ammo type amNothing
Thanks to KoBeWi