add -- to command line so that we can process files starting with - as per https://github.com/rg3/youtube-dl#how-do-i-download-a-video-starting-with-a---
add -- to command line so that we can process files starting with - as per https://github.com/rg3/youtube-dl#how-do-i-download-a-video-starting-with-a---

joglomedia/Youtube-dl-php,labzone/Youtube-dl-php