Committed Cael Aislinn's proposed commit: http://forums.nanotrasen.com/viewtopic.php?f=16&t=11641

- Xenos suit and helm (completely obscuring, and almost indistinguishable from drones) (admin spawned only for now). 
- Facehuggers now have different icon states for being thrown and after impregnation. 
- New death, unconscious and sleeping icons for aliens. 
- New icon (and projectile type) for neuroxotin. 
- New infection overlay images for telling aliens about pregnant humans (3 icons, showing the progression of the infestation). 
- New system for handling alien impregnation (alien embryos are an object inside the mob, instead of a disease). 
- Players can be operated surgically to remove the alien embryos (targetting the chest: scalpel, surgical saw, hemostat, retractors. If the embryo is nearly fully developed, it might come out alive though. 
- Corgis can now get impregnated. 
- There is a short animated overlay of a chestburster when it comes time to burst chests. 
- Alien larva now have three different icon sets, depending on their growth (25% they are bloody and pale, 25% - 75% they are pale, 75% onwards they are deep red).


Fixed up table smashing, and added rack smashing in the same way.
Added new north/south facing for the large alien queen.
Updated the changelog.

git-svn-id: http://tgstation13.googlecode.com/svn/trunk@5493 316c924e-a436-60f5-8080-3fe189b3f50e

code/datums/disease.dm

@@ -174,8 +174,8 @@ var/list/diseases = typesof(/datum/disease) - /datum/disease
 		if(resistance && !(type in affected_mob.resistances))
 			var/saved_type = "[type]"
 			affected_mob.resistances += text2path(saved_type)
-		if(istype(src, /datum/disease/alien_embryo))	//Get rid of the infection flag if it's a xeno embryo.
-			affected_mob.status_flags &= ~(XENO_HOST)
+		/*if(istype(src, /datum/disease/alien_embryo))	//Get rid of the infection flag if it's a xeno embryo.
+			affected_mob.status_flags &= ~(XENO_HOST)*/
 		affected_mob.viruses -= src		//remove the datum from the list
 	del(src)	//delete the datum to stop it processing
 	return

code/datums/diseases/alien_embryo.dm

@@ -1,5 +1,7 @@
 //affected_mob.contract_disease(new /datum/disease/alien_embryo)
 
+//cael - retained this file for legacy reference, see code\modules\mob\living\carbon\alien\special\alien_embryo.dm for replacement
+
 //Our own special process so that dead hosts still chestburst
 /datum/disease/alien_embryo/process()
 	if(!holder) return
@@ -97,6 +99,9 @@
 				gibbed = 1
 				return
 
+/datum/disease/alien_embryo/stage_change(var/old_stage)
+	RefreshInfectionImage()
+
 /*----------------------------------------
 Proc: RefreshInfectionImage()
 Des: Removes all infection images from aliens and places an infection image on all infected mobs for aliens.
@@ -106,7 +111,7 @@ Des: Removes all infection images from aliens and places an infection image on a
 		for (var/mob/living/carbon/alien/alien in player_list)
 			if (alien.client)
 				for(var/image/I in alien.client.images)
-					if(I.icon_state == "infected")
+					if(dd_hasprefix_case(I.icon_state, "infected"))
 						del(I)
 
 		for (var/mob/living/carbon/alien/alien in player_list)
@@ -114,7 +119,7 @@ Des: Removes all infection images from aliens and places an infection image on a
 				for (var/mob/living/carbon/C in mob_list)
 					if(C)
 						if (C.status_flags & XENO_HOST)
-							var/I = image('icons/mob/alien.dmi', loc = C, icon_state = "infected")
+							var/I = image('icons/mob/alien.dmi', loc = C, icon_state = "infected[stage]")
 							alien.client.images += I
 		return
 
@@ -127,7 +132,7 @@ Des: Checks if the passed mob (C) is infected with the alien egg, then gives eac
 		for (var/mob/living/carbon/alien/alien in player_list)
 			if (alien.client)
 				if (C.status_flags & XENO_HOST)
-					var/I = image('icons/mob/alien.dmi', loc = C, icon_state = "infected")
+					var/I = image('icons/mob/alien.dmi', loc = C, icon_state = "infected[stage]")
 					alien.client.images += I
 	return
 
@@ -142,6 +147,6 @@ Des: Removes the alien infection image from all aliens in the world located in p
 			if (alien.client)
 				for(var/image/I in alien.client.images)
 					if(I.loc == C)
-						if(I.icon_state == "infected")
+						if(dd_hasprefix_case(I.icon_state, "infected"))
 							del(I)
 	return