Change item handling: Import VoxBox code

VoxBox' item_drop code is much more stable and the item drop behaviour seems
to be much more “natural”. But it is incompatible with builtin_item, so this
mod must be disabled. Merging the builtin_item features is planned.

mods/builtin_item/init.lua

@@ -1,3 +1,9 @@
+--[==[
+NOTE: THIS MOD IS DISABLED IN MINECLONE 2!
+TODO: It should be merged with item_drop.
+
+
+
 minetest.register_entity(":__builtin:item", {
 	initial_properties = {
 		hp_max = 1,
@@ -200,3 +206,5 @@ minetest.register_entity(":__builtin:item", {
 if minetest.setting_get("log_mods") then
 	minetest.log("action", "[builtin_item] loaded.")
 end
+
+]==]