Nightshifts & Randomized Station Time

This commit adds the Nightshift lighting mode from /tg/. From 19:00 to
07:00 in station time, the station will go into a reduced-lighting mode,
with dimmed lights across the station.

In conjunction with this, there is a new configuration option to start
the shift time at a random time other than 12:00, so that players are
more likely to experience a night shift (as opposed to having to have a
7 hour round).

code/modules/modular_computers/file_system/programs/command/card.dm

@@ -259,7 +259,7 @@
 					var/title
 					var/content
 					if(mode == 2)
-						title = "crew manifest ([worldtime2text()])"
+						title = "crew manifest ([station_time_timestamp()])"
 						content = "<h4>Crew Manifest</h4><br>[data_core ? data_core.get_manifest(0) : ""]"
 					else if(modify && !mode)
 						title = "access report"