Nerfs reagent sprayers and /acid reagents

## Changes:
* /spray type items are 3 times slower than normal ranged weapons (4*3 = 12 delay in ticks (1.2 seconds)
* /chemsprayer/afterattack() copypasta removed
* Halves damage of /acid reagents for humans, since it is now a per limb damage
* Increase damage of /acid reagents to lesser /living mobs, since they still use an overall damage