Fixes not getting the hit message and sound (and logging) when the item embeds itself in a human.

Throwing a big item at an alien no longer pushes it.
If the item embeds itself in you, it doesn't push you.
Fixes an old argument in item/throw_impact() that I forgot to remove.
Rename the skip argument of hitby() to skipcatch (more explicit).

code/modules/mob/living/carbon/alien/alien_defense.dm

@@ -1,5 +1,5 @@
-/mob/living/carbon/alien/hitby(atom/movable/AM)
-	..(AM, skip = 1)
+/mob/living/carbon/alien/hitby(atom/movable/AM, skipcatch, hitpush)
+	..(AM, skipcatch = 1, hitpush = 0)
 
 
 /*Code for aliens attacking aliens. Because aliens act on a hivemind, I don't see them as very aggressive with each other.

code/modules/mob/living/carbon/carbon_defense.dm

@@ -1,5 +1,5 @@
-/mob/living/carbon/hitby(atom/movable/AM, skip)
-	if(!skip)	//ugly, but easy
+/mob/living/carbon/hitby(atom/movable/AM, skipcatch, hitpush = 1)
+	if(!skipcatch)	//ugly, but easy
 		if(in_throw_mode && !get_active_hand())	//empty active hand and we're in throw mode
 			if(canmove && !restrained())
 				if(istype(AM, /obj/item))
@@ -9,7 +9,7 @@
 						visible_message("<span class='warning'>[src] catches [I]!</span>")
 						throw_mode_off()
 						return 1
-	return ..()
+	..()
 
 /mob/living/carbon/throw_impact(atom/hit_atom)
 	. = ..()

code/modules/mob/living/carbon/human/human_defense.dm

@@ -455,6 +455,8 @@ emp_act
 		..()
 
 /mob/living/carbon/human/hitby(atom/movable/AM)
+	var/hitpush = 1
+	var/skipcatch = 0
 	if(AM.throw_speed >= EMBED_THROWSPEED_THRESHOLD)
 		if(istype(AM, /obj/item))
 			var/obj/item/I = AM
@@ -467,5 +469,6 @@ emp_act
 					I.loc = src
 					L.take_damage(I.w_class*I.embedded_impact_pain_multiplier)
 					visible_message("<span class='danger'>\the [I.name] embeds itself in [src]'s [L.getDisplayName()]!</span>","<span class='userdanger'>\the [I.name] embeds itself in your [L.getDisplayName()]!</span>")
-					return
-	return ..()
+					hitpush = 0
+					skipcatch = 1 //can't catch the now embedded item
+	return ..(AM, skipcatch, hitpush)

code/modules/mob/living/living_defense.dm

@@ -44,7 +44,7 @@
 		else
 				return 0
 
-/mob/living/hitby(atom/movable/AM)
+/mob/living/hitby(atom/movable/AM, skipcatch, hitpush = 1)
 	if(istype(AM, /obj/item))
 		var/obj/item/I = AM
 		var/zone = ran_zone("chest", 65)//Hits a random part of the body, geared towards the chest
@@ -75,7 +75,7 @@
 			add_logs(I.thrownby, src, "hit", I)
 	else
 		playsound(loc, 'sound/weapons/genhit.ogg', 50, 1, -1)
-	return ..()
+	..()
 
 /mob/living/mech_melee_attack(obj/mecha/M)
 	if(M.occupant.a_intent == "harm")