• Update SMSD SQL schema to version 18. Existing databases need the new
  inbox grouping columns and outbox SendDays column before upgrading.
• Add inbox multipart message grouping metadata and persist grouping state
  across SMSD restarts.
• Add weekday scheduling for the SMSD SQL outbox.
• Expose message IDs and timestamps to SMSD RunOn hooks.
• Prevent duplicate SMSD message processing and sending.
• Improve FILES backend validation, Unicode handling, and support for long
  and read-only outbox files.
• Improve SQL Server and Oracle support through ODBC.
• Improve SMS location enumeration for AT modems.
• Fix delivery report handling and multipart message recovery in SMSD.
• Fix configuration slot handling, monitor logging, Unicode conversion,
  Nokia network notifications, Huawei network time, and gnapgen contacts.
• Fix cross-platform build warnings and update documentation and
  localizations.