Port -tg-station cameranets

This should make it much easier to port abductors, if we ever want to do
that.

Changes:
  - Fixed a bug where the AI could not delete photos it takes.
  - Ported -tg- cameranets. This means that all of our camera based systems are more or less up to date with -tg-; 510 features are missing.
  - An AI with the 'camera lights' mode on will now, instead of the button toggling the closest camera's light, toggle camera lights on/off as the AI moves.
  - It now takes a minimum of 30 deciseconds between attempting to track someone, and locking on. This number is increased by their distance away from the AI eye.
  - The camera activate/deactivate proc is now called 'toggle_cam'.
  - The 'trackable' proc has been replaced by a more object-oriented 'mob.can_track()' proc.
  - The 'networks' section of the security camera console is now above the camera list.

In laymans terms: This refactors how security cameras calculate what
viewers can see, and adds a few neat features on top.

code/modules/mob/camera/camera.dm

@@ -8,7 +8,7 @@
 	mouse_opacity = 0
 	see_in_dark = 7
 	invisibility = 101 // No one can see us
-
+	sight = SEE_SELF
 	move_on_shuttle = 0
 
 /mob/camera/experience_pressure_difference()
@@ -17,7 +17,7 @@
 /mob/camera/Destroy()
 	..()
 	return QDEL_HINT_HARDDEL_NOW
-	
+
 /mob/camera/Login()
 	..()
 	update_interface()