The reagents datum now has its own flags, which currently includes
REAGENT_NOREACT, which functions in the same way. Shouldn't be touched
directly, use set_reacting(bool) to modify it, as modification also adds
or removes the reagents datum from the SSobj.processing list.
Also refactors cigs a little, adds a Destroy(), uses the open_flame()
proc for the hotspot exposure.
Jack Edge
bc113b6aa2