Twarc

This release includes a small change to `Twarc.connect` to catch read timeout errors which have been observed when using `--app_auth` to hydrate tweet ids.

The twarc command catches SIGTERM so that users can ctrl-c to stop the process. But previously it did so quietly, so as not to clutter up the console with a stack trace. But being quiet can be confusing when users put twarc into the background, and then log out, which can cause SIGTERM being sent to the process.

To aid in diagnosing twarc will now log when it has received a SIGTERM message before it stops. Thanks to mielverkerken for identifying the issue, and helping diagnose it.

We've seen a report of requests.exceptions.ChunkedEncodingError getting thrown occasionally. This commit catches those. Thanks for the bug report mthielk

This release includes a new command line option `--app_auth` that lets you control whether *App Auth* is used for connecting to the Twitter API instead of *User Auth* (the default).

This can be super useful in cases when you know the [rate limits](https://developer.twitter.com/en/docs/basics/rate-limits) are better for *App Auth* (search) but not so useful in cases where it isn't (hydration).

For example when using *User Auth* you are limited to issuing 180 request per 15 minutes, and with *App Auth* you can issue 450 requests per 15 minutes. If you are searching for a large number of tweets switching to App Auth means you can retrieve 4,320,000 tweets in 24 hours, as compared with 1,728,000.

This release includes a bug fix to the `twarc.Twarc.replies` method that was preventing it from fully processing quoted tweets as part of the conversation thread. Many thanks to freeatnet for noticing the problem and fixing it!