Fixes #803, fixes #226 (#809)

bugfix: "IV Drips not letting you set allowable rates."
tweak: "Min chemical volume lowered to avoid weird behaviour at low rates."
rscadd: "Examining an IV Drip will tell you the transfer rate."
bugfix: "Spiderbots are no longer invulnerable."
tweak: "Destroyed spiderbots will leave behind a brain."
tweak: "Spiderbot health increased from 10 to 25."

code/game/machinery/iv_drip.dm

@@ -153,6 +153,7 @@
 	if (!(user in view(2)) && user!=src.loc) return
 
 	user << "The IV drip is [mode ? "injecting" : "taking blood"]."
+	user << "<span class='notice'>The transfer rate is set to [src.transfer_amount] u/sec</span>"
 
 	if(beaker)
 		if(beaker.reagents && beaker.reagents.reagent_list.len)
@@ -177,7 +178,7 @@
 		return
 	set_rate:
 		var/amount = input("Set transfer rate as u/sec (between 4 and 0.001)") as num
-		if ((0.001 > transfer_amount || transfer_amount > 4) && transfer_amount != 0)
+		if ((0.001 > amount || amount > 4) && amount != 0)
 			usr << "<span class='warning'>Entered value must be between 0.001 and 4.</span>"
 			goto set_rate
 		if (transfer_amount == 0)

code/modules/mob/living/simple_animal/friendly/spiderbot.dm

@@ -24,8 +24,8 @@
 
 	wander = 0
 
-	health = 10
-	maxHealth = 10
+	health = 25
+	maxHealth = 25
 	hunger_enabled = 0
 
 	attacktext = "shocked"
@@ -212,10 +212,12 @@
 	if(camera)
 		camera.status = 0
 
-	held_item.loc = src.loc
-	held_item = null
+	if (held_item)
+		held_item.loc = src.loc
+		held_item = null
 
-	gibs(loc, viruses, null, null, /obj/effect/gibspawner/robot) //TODO: use gib() or refactor spiderbots into synthetics.
+	eject_brain()
+	gibs(loc, viruses, null, /obj/effect/gibspawner/robot) //TODO: use gib() or refactor spiderbots into synthetics.
 	qdel(src)
 	return
 

code/setup.dm

@@ -103,7 +103,7 @@
 #define CHEM_TOUCH 1
 #define CHEM_INGEST 2
 #define CHEM_BLOOD 3
-#define MINIMUM_CHEMICAL_VOLUME 0.01
+#define MINIMUM_CHEMICAL_VOLUME 0.001
 #define SOLID 1
 #define LIQUID 2
 #define GAS 3