V7 Documentation Updates

[jeremydmiller]

Jeremy has sprinted ahead in development and out paced documentation updates. This is tracking work that either hasn't been doc'd, or docs that could really use a refresh/review before 7.0

• IChangeListener.BeforeCommitAsync()
• Better discussion of IChangeListener in the asynchronous projections. Example of acting on aggregation changes. "at least once" vs "at most once" delivery guarantees
• Numeric revision tracking as an alternative to the current optimistic concurrency. Couple wrinkles in its usage to document
• Asynchronous version of FetchForWriting()
• Blue/green deployment of asynchronous projections
• Dynamic tenant database option
• Asynchronous daemon ownership changes, the potential for Marten to run in parallel.
• Try to refresh the "which projection type do I choose...."
• Really stress the importance of using FetchForWriting() in application code
• Native patching
• Document that compiled queries cannot use primary constructors
• Can use static Apply methods on projections
• Using logging with NpgsqlDataSource
• Async daemon error handling