Make new attributes pointers for each acquisition
To avoid plugin and driver manipulating the same attribute pointers at the same time.
This is only applicable with the commit that changes ptr->clear() to delete ptr in plugin.
This probably loses a bit of performance but guaranteees that the final data is not corrupted.
This was tested by purposedly bloating one vector pointer and passing it to plugin. It works: when vectors are created on driver and deleted on plugin, memory does not leak. If they are not deleted, memory leaks.