* Offset updates take place using TransactionWriter
* Refactor TransactionWriter in current state server
* Refactor TransactionWriter in federation sender
* Refactor TransactionWriter in key server
* Refactor TransactionWriter in media API
* Refactor TransactionWriter in server key API
* Refactor TransactionWriter in sync API
* Refactor TransactionWriter in user API
* Fix deadlocking Sync API tests
* Un-deadlock device database
* Fix appservice API
* Rename TransactionWriters to Writers
* Move writers up a layer in sync API
* Document sqlutil.Writer interface
* Add note to Writer documentation
* 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
* Fix New users appear in /keys/changes
* Create blank device keys when logging in on a new device
* Add PerformDeviceUpdate and fix a few bugs
- Correct device deletion query on sqlite
- Return no keys on /keys/query rather than an empty key
* Unbreak sqlite properly
* Use a real DB for currentstateserver integration tests
* Race fix
* Use TransactionWriter on other component SQLites
* Fix sync API tests
* Fix panic in media API
* Fix a couple of transactions
* Fix wrong query, add some logging output
* Add debug logging into StoreEvent
* Adjust InsertRoomNID
* Update logging