0.004   2015-12-18
        * Add is_refref() function!
        * Mention and compare to Scalar::Util::reftype.
        * Add benchmark results, including against reftype.
        * Add a note about the nature of playing with op trees, sort of.
        * Add a note on what functions from reftype() are not available.
        * Clarify how bad overloading is. No, it's not duck-typing either.

0.003   2015-12-17
        * Clarify overloading approach. Sorry, everyone!
        * Document :all option.

0.002   2015-12-05
        * Ugh PAUSE. Thanks, Graham Barr.

0.001   2015-12-04
        * First version