BayMerge Bugfix; Fixing guns, update computers. (#1263)

Fixes all the snowflake guns unique to our codebase with multiple firemodes so that they now actually behave correctly. Fixes a few bugs relating to computers, and updates modular_computers to use holoscreens.

code/modules/overmap/ships/computers/engine_control.dm

@@ -2,7 +2,7 @@
 
 /obj/machinery/computer/engines
 	name = "engine control console"
-	icon_keyboard = "tech_key"
+
 	icon_screen = "id"
 	var/state = "status"
 	var/list/engines = list()

code/modules/overmap/ships/computers/helm.dm

@@ -1,6 +1,6 @@
 /obj/machinery/computer/helm
 	name = "helm control console"
-	icon_keyboard = "med_key"
+
 	icon_screen = "id"
 	var/state = "status"
 	var/obj/effect/map/ship/linked			//connected overmap object