Merge branch 'master' of https://github.com/tgstation/-tg-station into listmos

Conflicts:
	code/controllers/subsystem/air.dm
	code/datums/gas_mixture.dm
	code/game/objects/items/devices/scanners.dm
	code/modules/mob/living/carbon/human/species.dm
	code/modules/mob/living/carbon/life.dm
	tgui/assets/tgui.css
	tgui/assets/tgui.js
	tgui/scripts/interfaces/atmos_filter.ract

code/modules/procedural mapping/mapGenerator.dm

@@ -38,7 +38,6 @@
 
 	if(replace)
 		undefineRegion()
-
 	map |= block(Start,End)
 	return map
 

code/modules/procedural mapping/mapGenerators/lava_river.dm

@@ -0,0 +1,18 @@
+/datum/mapGenerator/lavaland
+	var/start_z = 5
+	modules = list(/datum/mapGeneratorModule/river)
+
+/datum/mapGenerator/lavaland/defineRegion(turf/Start, turf/End, replace = 0)
+	start_z = Start.z
+	..()
+
+/datum/mapGeneratorModule/river
+	var/river_type = /turf/simulated/floor/plating/lava/smooth
+	var/river_nodes = 4
+	var/start_z = 5
+
+/datum/mapGeneratorModule/river/generate()
+	if(istype(mother, /datum/mapGenerator/lavaland))
+		var/datum/mapGenerator/lavaland/L = mother
+		start_z = L.start_z
+	spawn_rivers(start_z, river_nodes, river_type)