sing close() and fclose() return code checks.
- Add devices/ignore_suspended_devices to ignore suspended dm devices.
- Fix refresh_toolcontext() always to wipe persistent device filter cache.
- Long-lived processes write out persistent dev cache in refresh_toolcontext().
- Streamline dm_report_field_* interface.
- Update reporting man pages.
- Add --clustered to man pages.
- Add field definitions to report help text.