Baystation12 merchant port (#3155)

Port of the merchant mechanics from baystation12.
All of the trader, prices and most essential system are done, as well the job datum and the like. Mapping the shuttle, the base and a new dock will be done in a later pr.
Also adds phazon construction and several other items used in this pr.
The chance of the merchant slow being open at round start can be changed via the config, it is 20% by default.

code/modules/client/preferences_spawnpoints.dm

@@ -25,6 +25,7 @@ var/list/spawntypes = list()
 /datum/spawnpoint/arrivals
 	display_name = "Arrivals Shuttle"
 	msg = "is inbound from the NTCC Odin"
+	disallow_job = list("Merchant")
 
 
 /datum/spawnpoint/arrivals/New()
@@ -34,7 +35,7 @@ var/list/spawntypes = list()
 /datum/spawnpoint/cryo
 	display_name = "Cryogenic Storage"
 	msg = "has completed cryogenic revival"
-	disallow_job = list("Cyborg")
+	disallow_job = list("Cyborg", "Merchant")
 
 /datum/spawnpoint/cryo/New()
 	..()
@@ -43,8 +44,15 @@ var/list/spawntypes = list()
 /datum/spawnpoint/cyborg
 	display_name = "Cyborg Storage"
 	msg = "has been activated from storage"
-	restrict_job = list("Cyborg")
+	restrict_job = list("Cyborg", "Merchant")
 
 /datum/spawnpoint/cyborg/New()
 	..()
-	turfs = latejoin_cyborg
+	turfs = latejoin_cyborg
+
+/datum/spawnpoint/merchant
+	display_name = "Merchant Station"
+	restrict_job = list("Merchant")
+
+/datum/spawnpoint/merchant/New()
+	turfs = latejoin_merchant