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/games/minetest/WorlEditGenerator.java

@@ -51,7 +51,7 @@ public class WorlEditGenerator
         addIntMember("x", node.getX() - refNode.getX());
         addIntMember("y", node.getY() - refNode.getY());
         addIntMember("z", node.getZ() - refNode.getZ());
-        addStringMember("name",node.getMaterial());
+        addStringMember("name",node.getMaterial().toString() );
         luaNode.append("}");
         start=false;
     }