* 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