WIP minetest <-> laby import/export

- currently possible to export a laby into minetest
- start of a lua content parser to import .we into lab

java/org/artisanlogiciel/lua/LuaTuple.java

@@ -0,0 +1,32 @@
+package org.artisanlogiciel.lua;
+
+import java.util.ArrayList;
+import java.util.List;
+
+public class LuaTuple
+    extends  LuaObject
+{
+    List<LuaObject> items;
+
+
+    public LuaTuple() {
+        this.items = new ArrayList<>(2);
+    }
+
+    public LuaObject addItem(LuaObject item)
+    {
+        items.add(item);
+        return item;
+    }
+
+    @Override
+    public String toString() {
+        StringBuffer buffer  = new StringBuffer();
+        buffer.append('[');
+        buffer.append(items.get(0).toString());
+        buffer.append("]");
+        buffer.append('=');
+        buffer.append(items.get(1).toString());
+        return buffer.toString();
+    }
+}