Nerfs acid and cleans up /spray afterattack

* Adds banned_reagents list to reagent_containers
* Fixes chemsprayer afterattack() copypaste
* Acid reagents do half as much damage as before to humans
* Acid reagents do <B>more</B> damage to /living mobs that are not humans (old numbers were pathetic)
* /Spray containers fire 2x slower than other ranged weapons (Old PR had this at 3x)