Copy stable/9 to releng/9.3 as part of the 9.3-RELEASE cycle.

Approved by: re (implicit)
Sponsored by: The FreeBSD Foundation

Copy head to stable/9 as part of 9.0-RELEASE release cycle.

Approved by: re (implicit)

Update korean locale messages:

- Remove redundant `s' and `S' from yesexpr.
- Add fullwidth latin letters to yesexpr and noexpr (inspired by ja_JP.UTF-8).
- Add korean translated yesexpr (`Ye') and noexpr (`Anio').
- Add yesstr and nostr entries (inspired by zh_CN.*).
- Add UTF-8 encoded file and connect to build.