fix: should set idx-1 to a batch.keys.size before calling as_batch_destroy.
fix: should preload aerospike module.
fix: type name index is -2 if other data put in stack.
fix: should check module and function strings length.
change: scan and scanbackground functions has been implemented.
field "function" of struct las_apply_args_t has renamed to "func".
change: scan and udf arguments error message macros has been added.