Fixes current_cycle being incremented twice for certain reagents.
Fixes flash never working for /datum/effect/effect/system/reagents_explosion because of a typo.
Readding nitroglycerin reagent, it can now be stabilized with stabilizing agent and can explodes when exposed to 474K (like blackpowder).
Readjusted black powder explosion: no more flash (like nitroglycerin), tweaked the values a bit to not nerf blackpowder explosion.
Adding changelog.
phil235
edba4e0529