Converts reagents to use typepaths instead of IDs.
Centralises reagent spawning in a lot of places to use reagents_to_add instead of a variety of custom methods or initialise overrides.
Lit cigarettes now count as flame sources.
Changed the isflamesource proc from a general proc to an obj/item proc. It is tidier and will be easier to add future flame sources this way.
Removed some hardcoded flame stuff (Such as igniting rags and paper), which depending on an item being a type instead of just being something that could produce a flame. They now check to see if an item counts as a flame source.
Found leftover clown BS while updating paper burning code and killed it off.
