[pgpool-committers: 9873] pgpool: Doc: add release notes.

[Bo Peng]

Doc: add release notes.

Branch
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V4_2_STABLE

Details
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https://git.postgresql.org/gitweb?p=pgpool2.git;a=commitdiff;h=6d5f93f38b398b38ea31c42af859dac96844d071

Modified Files
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doc.ja/src/sgml/release-4.1.sgml | 180 ++++++++++++++++++++++++++++++++++
doc.ja/src/sgml/release-4.2.sgml | 195 ++++++++++++++++++++++++++++++++++++
doc/src/sgml/release-4.1.sgml    | 192 ++++++++++++++++++++++++++++++++++++
doc/src/sgml/release-4.2.sgml    | 207 +++++++++++++++++++++++++++++++++++++++
4 files changed, 774 insertions(+)