Overdose Change, Reagent Tweaks and Fixes, IPC Damage Fixes

Adjusts how Overdosing works
- Overdose effects now stop if you have less than the overdose threshold
for the given reagent in your system
- Previously, overdose effects would continue until all of the reagent
was removed from the body
- After dropping below the overdose threshold, reagents will process as
normal as long as they do not surpass the threshold again.

Tweaked some Synthetic-oriented reagents
- Synthetic drugs no longer will cause Toxins damage
- The toxins damage for these has been replaced with either another form
of damage or side-effect
- Degreaser no longer cures Toxins Damage in Synthetics
- Degreaser still acts as a chemical purgative and lube cleaner, but
helps cure certain side-effects much like Coffee does for organics.

Sterlizine recipe changed to require antihol and chlorine
- Effectively the same as the old recipe, except actually mixable
- Fixes #2030

Increases max_damage of MMI Holders to 200 (from 60)
- Now matches the max_damage for organic brains
- Should make IPC brain damage more consistent with organic brain damage

Gives IPCs the NO_POISON flag
- This should make IPCs immune to toxins damage again, as intended
originally.
- Fixes #2151.

code/modules/organs/subtypes/machine.dm

@@ -5,14 +5,14 @@
 	max_damage = 50 //made same as arm, since it is not vital
 	min_broken_damage = 30
 	encased = null
-	
+
 /obj/item/organ/external/head/ipc/New()
 	robotize("Morpheus Cyberkinetics")
 	..()
 
 /obj/item/organ/external/chest/ipc
 	encased = null
-	
+
 /obj/item/organ/external/chest/ipc/New()
 	robotize("Morpheus Cyberkinetics")
 	..()
@@ -91,6 +91,7 @@
 	organ_tag = "brain"
 	parent_organ = "chest"
 	vital = 1
+	max_damage = 200
 	var/obj/item/device/mmi/stored_mmi
 
 /obj/item/organ/mmi_holder/proc/update_from_mmi()