• #620: With the "create" action and the "--list" ("--files") flag, only show excluded files at
  verbosity 2.
• #621: Add optional authentication to the ntfy monitoring hook.
• With the "create" action, only one of "--list" ("--files") and "--progress" flags can be used.
  This lines up with the new behavior in Borg 2.0.0b5.
• Internally support new Borg 2.0.0b5 "--filter" status characters / item flags for the "create"
  action.
• Fix the "create" action with the "--dry-run" flag querying for databases when a PostgreSQL/MySQL
  "all" database is configured. Now, these queries are skipped due to the dry run.
• Add "--repository" flag to the "rcreate" action to optionally select one configured repository to
  create.
• Add "--progress" flag to the "transfer" action, new in Borg 2.0.0b5.
• Add "checkpoint_volume" configuration option to creates checkpoints every specified number of
  bytes during a long-running backup, new in Borg 2.0.0b5.