Mirsal
This PR adds an archive mode in which there is no initial sync, and aws sync commands are run without the --delete flag, allowing for continuous archiving of local content...
### Before submitting a *pull request* make sure you have: - [x] At least skimmed through [adding new extractor tutorial](https://github.com/rg3/youtube-dl#adding-support-for-a-new-site) and [youtube-dl coding conventions](https://github.com/rg3/youtube-dl#youtube-dl-coding-conventions) sections - [x] [Searched](https://github.com/rg3/youtube-dl/search?q=is%3Apr&type=Issues) the bugtracker...