Camera fixes and performance tweaks.

Improves camera EMP handling. Now uses a var and processing to determine when the EMP should end, preventing inconsistent states when a camera is EMPd multiple times.

Reduces the process and bandwidth need for cameras.
* There is now a common camera repository, responsible for setting up cameras once for every invalidation.
* Camera consoles now only updates when the camera cache is invalidated, not every second.
* The console now only presents one network at a time, and only sends the data necessary to view that network (as opposed to sending the data for all cameras).

code/datums/repositories/cameras.dm

@@ -0,0 +1,34 @@
+var/global/datum/repository/cameras/camera_repository = new()
+
+/proc/invalidateCameraCache()
+	camera_repository.networks.Cut()
+	camera_repository.invalidated = 1
+	camera_repository.camera_cache_id = (++camera_repository.camera_cache_id % 999999)
+
+/datum/repository/cameras
+	var/list/networks
+	var/invalidated = 1
+	var/camera_cache_id = 1
+
+/datum/repository/cameras/New()
+	networks = list()
+	..()
+
+/datum/repository/cameras/proc/cameras_in_network(var/network)
+	setup_cache()
+	var/list/network_list = networks[network]
+	return network_list
+
+/datum/repository/cameras/proc/setup_cache()
+	if(!invalidated)
+		return
+	invalidated = 0
+
+	cameranet.process_sort()
+	for(var/obj/machinery/camera/C in cameranet.cameras)
+		var/cam = C.nano_structure()
+		for(var/network in C.network)
+			if(!networks[network])
+				networks[network] = list()
+			var/list/netlist = networks[network]
+			netlist[++netlist.len] = cam

code/datums/repositories/crew.dm

@@ -1,9 +1,5 @@
 var/global/datum/repository/crew/crew_repository = new()
 
-/datum/cache_entry
-	var/timestamp
-	var/data
-
 /datum/repository/crew
 	var/list/cache_data
 

code/datums/repositories/repository.dm

@@ -0,0 +1,4 @@
+/datum/cache_entry
+	var/timestamp
+	var/data
+