test: enhance fs-watch-recursive test

This patch

  - issues a TAP plugin parsable message on non darwin/windows boxes
  - uses `const` wherever applicable
  - moves the test to parallel

PR-URL: https://github.com/nodejs/node/pull/2599


Reviewed-By: Ben Noordhuis <info@bnoordhuis.nl>
Reviewed-By: Johan Bergström <bugs@bergstroem.nu>
Reviewed-By: James M Snell <jasnell@gmail.com>