Ports holomap blueprints from tg/vg.

Changes:
 - Clicking "view structural data" in the station blueprints menu will
   show you ghost images of where things like disposal pipes, wires,
   atmospherics pipes, and other power machinery are originally supposed
   to go. Note, this will show you the ghost images over turfs even if the
   machinery is destroyed.

code/ATMOSPHERICS/atmospherics.dm

@@ -16,6 +16,7 @@ Pipelines + Other Objects -> Pipe network
 	idle_power_usage = 0
 	active_power_usage = 0
 	power_channel = ENVIRON
+	on_blueprints = TRUE
 	var/nodealert = 0
 	var/can_unwrench = 0