doubledash hygiene for external cmd: sudo, AND

also includes doubledash hygiene for any child commands following each sudo
doubledash hygiene for external cmd: mv
doubledash hygiene for external cmd: ln
doubledash hygiene for external cmd: ls
doubledash hygiene for external cmd: stat
doubledash hygiene for external cmd: rm
doubledash hygiene for external cmd: ditto
doubledash hygiene for external cmd: open
doubledash hygiene for external cmd: rmdir
doubledash hygiene for external cmd: launchctl
doubledash hygiene for external cmd: chmod
doubledash hygiene for external cmd: kextunload
doubledash hygiene for external cmd: file
Merge pull request #2613 from rolandwalker/double_dash

Doubledash hygiene for external commands