As of the `v2.0.0` release of this project, only users who are authenticated with a particular OAuth server can _create_ feeds. Any federated user can still read the feeds. I implemented this because running this service in the open invited thousands of spammers to create feeds and overwhelm the service. With this new model, you can run this as an added bonus for people in a community like a Mastodon server, and as the person running it you are taking on only the moderation burden of the users you are already responsible for on your federated server.
This commit mostly fixes the duplicate messages issue. What was happening was I was creating multiple Note objects if I was sending a Note to multiple people. Instead I create one Note object and reference that in multiple Create events.
This adds a `summary` field to the `actor` object, populated from
the RSS feed's top level <description> element. This makes the
<description> content into the profile description.
