New --patchline argument

[LeagueOfPoro]

Added support for --patchline pbe argument as a working alternative to --cdn.

[LeagueOfPoro]

Thanks for your comment. Based on that, I replaced --patchline pbe with a simple --pbe. This way it defaults to live when not set and pbe if the flag is present.

[benoitryder]

Keeping --patchline is better IMHO, because it's more generic and matches directly the storage JSON format.

And you can use the following to have same default/fallback behavior:

    storage_parser.add_argument('--patchline', choices=['live', 'pbe'], default=None,
                                help="use PBE patchline")

        if args.patchline is not None:
            if conf['type'] == 'patcher':
                conf['patchline'] = args.patchline
            else:
                parser.error("--patchline is only supported for 'patcher' storage")

[LeagueOfPoro]

I would argue --pbe makes for a more concise command. However, matching the JSON config makes sense. Changed