* Initial federation sender -> federation API refactoring
* Move base into own package, avoids import cycle
* Fix build errors
* Fix tests
* Add signing key server tables
* Try to fold signing key server into federation API
* Fix dendritejs builds
* Update embedded interfaces
* Fix panic, fix lint error
* Update configs, docker
* Rename some things
* Reuse same keyring on the implementing side
* Fix federation tests, `NewBaseDendrite` can accept freeform options
* Fix build
* Update create_db, configs
* Name tables back
* Don't rename federationsender consumer for now
* Updated TransactionWriters, moved locks in roomserver, various other tweaks
* Fix redaction deadlocks
* Fix lint issue
* Rename SQLiteTransactionWriter to ExclusiveTransactionWriter
* Fix us not sending transactions through in latest events updater
* Initial persistence of blacklists
* Move statistics folder
* Make MaxFederationRetries configurable
* Set lower failure thresholds for Yggdrasil demos
* Still write events into database for blacklisted hosts (they can be tidied up later)
* Review comments