clarify laziness of blocks and added more care to context execution

src/main/java/carpet/script/value/BlockValue.java

@@ -144,8 +144,6 @@ public class BlockValue extends Value
             }
             if (v1 instanceof BlockValue)
             {
-                ((BlockValue) v1).getBlockState();
-                ((BlockValue) v1).getData();
                 return new LocatorResult(((BlockValue) v1), 1+offset);
             }
             if (v1 instanceof ListValue)
@@ -256,7 +254,7 @@ public class BlockValue extends Value
     @Override
     public Value clone()
     {
-        return new BlockValue(blockState, world, pos);
+        return new BlockValue(blockState, world, pos, data);
     }
 
     @Override

src/main/java/carpet/script/value/Value.java

@@ -48,6 +48,7 @@ public abstract class Value implements Comparable<Value>, Cloneable
         {
             // should not happen
             e.printStackTrace();
+            throw new InternalExpressionException("Variable of type "+getTypeString()+" is not cloneable. Tell gnembon about it, this shoudn't happen");
         }
         copy.boundVariable = var;
         return copy;