Introduce a new MACRO to check if the data is a String object and
update existing MACROs to include the actual object description to
be printed in case of an error.
PR-URL: https://github.com/nodejs/node/pull/3100
Reviewed-By: Ben Noordhuis <info@bnoordhuis.nl>
Reviewed-By: Fedor Indutny <fedor.indutny@gmail.com>
Reviewed-By: James M Snell <jasnell@gmail.com>
