Architecture

Arguments are passed to an instance of RedditDownloader
Internal objects are created
- Formatter created
- Filter created
- Configuration loaded
- Reddit instance created
Reddit lists scraped

To actually download, the following happens:

RedditDownloader uses DownloadFactory to find the right module for a submission
Downloader instance created
Downloader returns a list of Resource objects (lists may have one objects)
RedditDownloader checks if it already exists
RedditDownloader checks against the DownloadFilter created earlier
RedditDownloader creates a formatted file path base on the Resource with FileNameFormatter
Resource content is written to disk