Unapologetic Diona Buffs (#8090)

Biomass is now less strong.
Diona have gotten a ton of minor code improvements, using their abilities should now be a little sane.
Diona nymphs don't have to be whitelisted to grow until a full diona now. Administrative action will be taken if this right is abused.
Diona gestalts can now use their biomass / arms to create biomass structures.
Removed nymphs' ability to open biomass walls. It was buggy.

code/modules/materials/materials.dm

@@ -397,7 +397,12 @@ var/list/name_to_material
 	icon_colour = null
 	stack_type = null
 	icon_base = "biomass"
-	integrity = 600
+	integrity = 100
+	// below is same as wood
+	melting_point = T0C + 300
+	ignition_point = T0C + 288
+	golem = "Wood Golem"
+	hitsound = 'sound/effects/woodhit.ogg'
 
 /material/diona/place_dismantled_product()
 	return