WinRT: Locale handling support

Provides locale-related codepaths for WinRT where existing Win32 API is
unsupported.

Change-Id: I35b83d6b208165b7660cac3c9b383cb6ba7e5cf9
Done-with: Maurice Kalinowski
Reviewed-by: Andrew Knight <andrew.knight@digia.com>
Reviewed-by: Friedemann Kleint <Friedemann.Kleint@digia.com>
Mark some members in the event Unix dispatchers as final

Improves the code generation by not making virtual calls where not
necessary.

Change-Id: I908905f4430359eea3ea8548a35e83e028805911
Reviewed-by: Marc Mutz <marc.mutz@kdab.com>
Reviewed-by: Robin Burchell <robin+qt@viroteck.net>