Ventcrawling fixes

d3athrow/vgstation13#4251
tgstation/-tg-station#9296

 - Fixes moving between pipeline datums not updating pipe vision
 - Fixes login() not updating pipe vision
 - Removes hardcoded limit of entering through unary machinery-- does
   nothing *now*
 - Can see pipes in darkness as fullbright
 - More sanity checks

code/ATMOSPHERICS/components/unary/unary_base.dm

@@ -66,7 +66,7 @@
 	return_network(obj/machinery/atmospherics/reference)
 		build_network()
 
-		if(reference==node)
+		if(reference == node || reference == src)
 			return network
 
 		return null
@@ -89,7 +89,7 @@
 		if(reference==node)
 			del(network)
 			node = null
-			
+
 		update_icon()
 		update_underlays()