Adds Bughunt, Incursion, Spy vs Spy, Tower Defense (#7698)

rscadd: "Added three new gamemodes: Tower Defense, Bughunt, Spy vs. Spy."
    rscadd: "Bughunt, mercenary and borer, needs twenty required players and five required enemies."
    tweak: "Borers have received some miscellaneous fixes and tweaks across the board. They should overall work better now."
    rscadd: "Borers can now awaken psionics in their hosts. Maybe it's not a bad idea to get a brain slug after all..."
    rscadd: "Spy vs. Spy, traitor and renegade, needs four required players."
    tweak: "Changed how renegades work a bit. You're not traitors! You're paranoid people who smuggled a gun to work and are working to keep themselves safe."
    rscadd: "Tower Defense, mercenary, heist and ninjas, needs thirty required players and ten required enemies. Good luck!"

code/modules/organs/internal/brain.dm

@@ -52,7 +52,7 @@
 	var/mob/living/simple_animal/borer/borer = owner.has_brain_worms()
 
 	if(borer)
-		borer.detatch() //Should remove borer if the brain is removed - RR
+		borer.detach() //Should remove borer if the brain is removed - RR
 
 	var/obj/item/organ/internal/brain/B = src
 	if(istype(B) && istype(owner))

code/modules/organs/misc.dm

@@ -1,26 +1,4 @@
-//CORTICAL BORER ORGANS.
-/obj/item/organ/borer/process()
-
-	// Borer husks regenerate health, feel no pain, and are resistant to stuns and brainloss.
-	for(var/chem in list("tricordrazine","tramadol","hyperzine","alkysine"))
-		if(owner.reagents.get_reagent_amount(chem) < 3)
-			owner.reagents.add_reagent(chem, 5)
-
-	// They're also super gross and ooze ichor.
-	if(prob(5))
-		var/mob/living/carbon/human/H = owner
-		if(!istype(H))
-			return
-
-		var/datum/reagent/blood/B = locate(/datum/reagent/blood) in H.vessel.reagent_list
-		blood_splatter(H,B,1)
-		var/obj/effect/decal/cleanable/blood/splatter/goo = locate() in get_turf(owner)
-		if(goo)
-			goo.name = "husk ichor"
-			goo.desc = "It's thick and stinks of decay."
-			goo.basecolor = "#412464"
-			goo.update_icon()
-
+// This borer is the worm that replaced the host's brain, not the brainworm latched onto a brain
 /obj/item/organ/borer
 	name = "cortical borer"
 	icon = 'icons/obj/objects.dmi'
@@ -28,10 +6,9 @@
 	organ_tag = BP_BRAIN
 	desc = "A disgusting space slug."
 	parent_organ = BP_HEAD
-	vital = 1
+	vital = TRUE
 
 /obj/item/organ/borer/removed(var/mob/living/user)
-
 	..()
 
 	var/mob/living/simple_animal/borer/B = owner.has_brain_worms()
@@ -39,8 +16,7 @@
 		B.leave_host()
 		B.ckey = owner.ckey
 
-	spawn(0)
-		qdel(src)
+	qdel(src)
 
 //VOX ORGANS.
 /obj/item/organ/internal/stack