Used in create_part, kill_part, and part_change_type, allows us to remove element-specific stuff in those functions
Note: difference between Create and ChangeType is that Create is called when we want to initialize default element properties, but ChangeType is called every time a particle is changed to that type, even if it doesn't need default properties set. ChangeType is mainly used for things that need accurate state tracking, like the stkm spawn status.
ChangeType is called every time a particle is changed to or from its type, which includes if the particle is deleted, and also Lua.
Neither of these functions are called when loading saves, that's probably an oversight, will fix later
The rest will will in a commit soon that adds the Create event and some other stuff
Lua events will come after that
PLSM default temp lowered to MAX_TEMP
