RUST additions and updates, Modular guns, and Lead. (#4667)

* expanding rupture procs
adds hydromagnetic traps for power production.

* Minor tweaks.

* Adds modular guns using research components.

* Updates materials to have a radiation_resistance variable, used in calculating radiation. Adds Lead as a material.

* Un-zeros stock material radiation resistance.

* Adds, and enables four 'end-events' for the RUST in place of the old Rupture() proc.

* Map muckery?

* absolute pathing i guess?

* getting angry, travis.

* TRAVIS
STAHP

* I...
Comments? Lists? Who the hell knows.

code/modules/materials/material_sheets.dm

@@ -94,6 +94,13 @@
 	apply_colour = 1
 	no_variants = FALSE
 
+/obj/item/stack/material/lead
+	name = "lead"
+	icon_state = "sheet-adamantine"
+	default_type = "lead"
+	apply_colour = 1
+	no_variants = TRUE
+
 /obj/item/stack/material/sandstone
 	name = "sandstone brick"
 	icon_state = "sheet-sandstone"