Mac uses the CLDR format codes which need to be translated into their
Qt equivalent. The existing code mistranslates the year code, is
outdated for a number of new codes introduced in recent versions of
CLDR, and by default accepted any codes it didn't recognize.
This change updates support to the latest version of CLDR, fixes the
treatment of years, and defaults to ignoring any new format codes
added in the future.
Note that this change cannot have auto tests written as the system
locale formats change between versions of OSX. Testing must be
done manually by changing system locale and formats.
Task-number: QTBUG-25057
Change-Id: I69dda25b4a0b38d3971995644546306876922d57
Reviewed-by: Morten Johan Sørvig <morten.sorvig@digia.com>