Special Swords and amputation (#715)

changes:

rscadd: "Chainswords now have an improved animation."
rscadd: "Chainswords and energy blades can no longer get embedded in people."
rscadd: "Chainswords and energy blades can now be used as surgical tools to amputate limbs. Chainswords are messy. Energy blades will cut clean and cauterize the wound"
tweak: "Surgery messages about amputating bodyparts are now very noticeable"
tweak: "Cauterising wounds with a welding tool is much more reliable. Cauterising with a cigarette is no longer effective."
bugfix: "Fixed chainsword held sprite not updating when toggled"

code/game/objects/items.dm

@@ -36,6 +36,7 @@
 	var/siemens_coefficient = 1 // for electrical admittance/conductance (electrocution checks and shit)
 	var/slowdown = 0 // How much clothing is slowing you down. Negative values speeds you up
 	var/canremove = 1 //Mostly for Ninja code at this point but basically will not allow the item to be removed if set to 0. /N
+	var/can_embed = 1//If zero, this item/weapon cannot become embedded in people when you hit them with it
 	var/list/armor = list(melee = 0, bullet = 0, laser = 0,energy = 0, bomb = 0, bio = 0, rad = 0)
 	var/list/allowed = null //suit storage stuff.
 	var/obj/item/device/uplink/hidden/hidden_uplink = null // All items can have an uplink hidden inside, just remember to add the triggers.