Add option to turn off fortresses

Some people just can't stand the coolness.

config.lua

@@ -50,6 +50,9 @@ setting("number", "fortcha", 0.0003) --chance of fortresses
 --realm limits for Dungeon Masters' Lair
 setting("number", "dm_top", -4000) --upper limit 
 setting("number", "dm_bot", -5000) --lower limit 
+--should fortresses and fountains spawn?
+setting("bool", "fortresses", true)
+setting("bool", "fountains", true)
 
 --minimum number of items in chests found in fortresses
 setting("number", "min_items", 2)

init.lua

@@ -22,6 +22,9 @@ if caverealms.config.falling_icicles == true then
 	print("[caverealms] falling icicles enabled.")
 end
 
+local FORTRESSES = caverealms.config.fortresses --true | Should fortresses spawn?
+local FOUNTAINS = caverealms.config.fountains --true | Should fountains spawn?
+
 -- Parameters
 
 local YMIN = caverealms.config.ymin -- Approximate realm limits.
@@ -284,10 +287,10 @@ minetest.register_on_generated(function(minp, maxp, seed)
 							if math.random() < FLACHA then --neverending flames
 								data[ai] = c_flame
 							end
-							if math.random() < FOUNCHA then --DM FOUNTAIN
+							if math.random() < FOUNCHA and FOUNTAINS then --DM FOUNTAIN
 								data[ai] = c_fountain
 							end
-							if math.random() < FORTCHA then --DM FORTRESS
+							if math.random() < FORTCHA and FORTRESSES then --DM FORTRESS
 								data[ai] = c_fortress
 							end
 						end