v2.9.0

Fixes

• Fixed a bug in TimeRotatingFileHandler. (#287)

Improvements

• Renamed backend_thread_error_handler to backend_thread_notifications_handler in Config.h. Previously this
  handler was used only to report errors from the backend worker thread to the user. This callback will also now report
  info messages to the user.
• Report unbounded spsc queue reallocation via
  the backend_thread_notifications_handler. (#286)
• Report bounded spsc queue dropped messages via the backend_thread_notifications_handler.