Centralise all command aliases

This should avoid any crashes on startup because worldedit.alias_command 
is nil too (strange!)

worldeditadditions/lib/bonemeal.lua

@@ -59,5 +59,3 @@ function worldeditadditions.bonemeal(pos1, pos2, strength, chance)
 	
 	return true, nodes_bonemealed, candidates
 end
-
-worldedit.alias_command("flora", "bonemeal")

worldeditadditions_commands/commands/convolve.lua

@@ -72,6 +72,3 @@ worldedit.register_command("convolve", {
 		return true, "Added "..stats.added.." and removed "..stats.removed.." nodes in " .. time_taken .. "s"
 	end
 })
-
-worldedit.alias_command("smoothadv", "convolve")
-worldedit.alias_command("conv", "convolve")

worldeditadditions_commands/commands/layers.lua

@@ -31,6 +31,3 @@ worldedit.register_command("layers", {
 		return true, changes.replaced .. " nodes replaced and " .. changes.skipped_columns .. " columns skipped in " .. time_taken .. "s"
 	end
 })
-
-worldedit.alias_command("naturalise", "layers")
-worldedit.alias_command("naturalize", "layers")

worldeditadditions_commands/init.lua

@@ -35,3 +35,12 @@ if minetest.get_modpath("bonemeal") then
 else
 	minetest.log("action", "[WorldEditAdditions] bonemeal mod not detected: //bonemeal command not registered (if you see this message and you're using an alternative mod that provides bonemeal, please get in touch by opening an issue)")
 end
+
+
+worldedit.alias_command("smoothadv", "convolve")
+worldedit.alias_command("conv", "convolve")
+
+worldedit.alias_command("naturalise", "layers")
+worldedit.alias_command("naturalize", "layers")
+
+worldedit.alias_command("flora", "bonemeal")