A method to grab the comments from YouTube videos

* Requires qwarc and realpath from GNU coreutils 8.23+.
* Execute as `comments VIDEOID` where `VIDEOID` is the 11-character video ID from YouTube.
* You can pass multiple video IDs at once as well: `comments VIDEOID1 VIDEOID2 ...`. They get executed sequentially.
* Comments are grabbed in all available sort orders (i.e. "top" and "new", though "top" is retrieved twice since YT returns two continuation tokens for it), including replies and nesting.
* The "top" sort order sometimes doesn't return all comments but might be missing some. The reason for this is unclear.
* On videos with many comments, the "top" sort order retrieval will fail rapidly due to the continuation token being too long and causing an HTTP 413 Request Entity Too Large error.
* Also on videos with many comments, the "new" sort order retrieval will fail a bit less rapidly due to deep recursion.
* Everything's written to a few files in the current directory called `youtube-comments-VIDEOID-DATE*`.
 * After the retrieval finished cleanly and you're satisfied with the results, you can delete the `.db` and `.log` files. The former is essentially useless, and the latter is contained in the `-meta.warc.gz` file.