New utility: pkg_radd

Matthias Schmidt has committed Simon ‘corecode’ Schubert’s pkg_radd, a wrapper script that allows installation of pkgsrc binaries, even if there isn’t a local pkgsrc tree. Check the commit message for an explanation, or the script itself for the details. Note that this is a DragonFly-specific pkgsrc utility, meaning it doesn’t appear on any other pkgsrc platform.