Updates Tools

Adds toolspeed var, which is a multiplier on how 'fast' the tool works.  0.5 means it goes twice as fast.
Adds usesound var, which determines what sound is used when a tool is being used.
Changes a lot of code to use those two vars instead.
Adds 'ayyy' tools, which are ported from /tg/'s abductor gamemode.  They're currently admin only but I might make them obtainable by xenoarch later.
Adds powertools, also from /tg/.  CE starts with them in a new toolbelt that spawns in their locker, ported from (you guessed it) /tg/.
Changes welder sprites to look nicer, ported yet again from /tg/.  Modified the blue welder slightly so it can be the electric welder sprite.
Adds various sounds from /tg/, for tools and welders.

code/modules/assembly/shock_kit.dm

@@ -30,6 +30,7 @@
 	if(istype(W, /obj/item/weapon/screwdriver))
 		status = !status
 		to_chat(user, "<span class='notice'>[src] is now [status ? "secured" : "unsecured"]!</span>")
+		playsound(src, W.usesound, 50, 1)
 	add_fingerprint(user)
 	return