doesn't yet compile or work.
needs to actually add the peeking block into the sync response.
checking in now before it gets any bigger, and to gather any initial feedback on the vague shape of it.
* 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
* Initial pass at refactoring config (not finished)
* Don't forget current state and EDU servers
* More shifting around
* Update server key API tests
* Fix roomserver test
* Fix more tests
* Further tweaks
* Fix current state server test (sort of)
* Maybe fix appservices
* Fix client API test
* Include database connection string in database options
* Fix sync API build
* Update config test
* Fix unit tests
* Fix federation sender build
* Fix gobind build
* Set Listen address for all services in HTTP monolith mode
* Validate config, reinstate appservice derived in directory, tweaks
* Tweak federation API test
* Set MaxOpenConnections/MaxIdleConnections to previous values
* Update generate-config
* Add support for logs in StreamingToken
Tokens now end up looking like `s11_22|dl-0-123|ab-0-12224`
where `dl` and `ab` are log names, `0` is the partition and
`123` and `12224` are the offsets.
* Also test reserialisation
* s/|/./g so tokens url escape nicely
* 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
* Deduplicate FS database, add some EDU persistence groundwork
* Extend TransactionWriter to use optional existing transaction, use that for FS SQLite database writes
* Fix build due to bad keyserver import
* Working EDU persistence
* gocyclo, unsurprisingly
* Remove unused
* Update copyright notices