2.3.0

Changes:

• Load DNS overwrite config on startup (from https://github.com/NullIsNot0) ce938bb
• Remove duplicates from identity store before email notifications (from https://github.com/NullIsNot0) be915ae
• Fix room name retrieval after Synapse dropped table room_names (from https://github.com/NullIsNot0) 6b7a4c8
• Add logging configuration. Add --dump and --dump-and-exit options to just print the full configuration. 9219bd4 aed12e5
• Add the postgresql backend for internal storage. 7555fff 72977d6
• Improve logging configuration. Introduce the root and the app log levels. 75efd99