v0.12.3

• Breaking change: Added logging for row iteration in the dbutil package. This changes the return type of Query methods from *sql.Rows to a new dbutil.Rows interface.
• Added flag to disable wrapping database upgrades in a transaction (e.g. to allow setting PRAGMAs for advanced table mutations on SQLite).
• Deprecated MessageEventContent.GetReplyTo in favor of directly using RelatesTo.GetReplyTo. RelatesTo methods are nil-safe, so checking if RelatesTo is nil is not necessary for using those methods.
• Added wrapper for space hierarchyendpoint (thanks to @mgcm in #100).
• Added bridge config option to handle transactions asynchronously.
• Added separate channels for to-device events in appservice transaction handler to avoid blocking to-device events behind normal events.
• Added RelatesTo.GetNonFallbackReplyTo utility method to get the reply event ID, unless the reply is a thread fallback.
• Added event.TextToHTML as an utility method to HTML-escape a string and replace newlines with <br/>.
• Added check to bridge encryption helper to make sure the e2ee keys are still on the server. Synapse is known to sometimes lose keys randomly.
• Changed bridge crypto syncer to crash on M_UNKNOWN_TOKEN errors instead of retrying forever pointlessly.
• Fixed verifying signatures of fallback one-time keys.