Moontest compatibility, griefing resistance

My visit to OldCoder's Moontest server revealed that CaveRealms was
incompatible with Moontest... but no more!  Additionally, griefing in
creative mode was possible because fortress and fountain spawners
appeared in the creative inventory... also fixed.  Other measures in
development...

init.lua

@@ -115,6 +115,12 @@ minetest.register_on_generated(function(minp, maxp, seed)
 	--grab content IDs
 	local c_air = minetest.get_content_id("air")
 	local c_stone = minetest.get_content_id("default:stone")
+	
+	if (minetest.get_modpath("moontest")) then
+		c_air = minetest.get_content_id("moontest:vacuum")
+		c_stone = minetest.get_content_id("moontest:stone")
+	end
+	
 	local c_water = minetest.get_content_id("default:water_source")
 	local c_lava = minetest.get_content_id("default:lava_source")
 	local c_ice = minetest.get_content_id("default:ice")

nodes.lua

@@ -525,7 +525,7 @@ minetest.register_node("caverealms:constant_flame", {
 	}},
 	inventory_image = "fire_basic_flame.png",
 	light_source = 14,
-	groups = {igniter=2,dig_immediate=3,hot=3},
+	groups = {igniter=2,dig_immediate=3,hot=3, not_in_creative_inventory=1},
 	drop = '',
 	walkable = false,
 	buildable_to = true,
@@ -545,7 +545,7 @@ minetest.register_node("caverealms:s_chest", {
 	description = "Trying to rob the bank before it's opened, eh?",
 	tiles = {"default_chest_front.png"},
 	paramtype2 = "facedir",
-	groups = {choppy=3,oddly_breakable_by_hand=2,cavechest=1},
+	groups = {choppy=3,oddly_breakable_by_hand=2,cavechest=1, not_in_creative_inventory=1},
 })
 
 --hacky schematic placers
@@ -553,13 +553,13 @@ minetest.register_node("caverealms:s_chest", {
 minetest.register_node("caverealms:s_fountain", {
 	description = "A Hack like you should know what this does...",
 	tiles = {"caverealms_stone_eyes.png"},
-	groups = {crumbly=3, schema=1},
+	groups = {crumbly=3, schema=1, not_in_creative_inventory=1},
 })
 
 minetest.register_node("caverealms:s_fortress", {
 	description = "A Hack like you should know what this does...",
 	tiles = {"caverealms_stone_eyes.png"},
-	groups = {crumbly=3, schema=1},
+	groups = {crumbly=3, schema=1, not_in_creative_inventory=1},
 })
 
 --dungeon master statue (nodebox)