[pgpool-committers: 8976] pgpool: Doc: add release note.

[Bo Peng]

Doc: add release note.

Branch
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V4_0_STABLE

Details
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https://git.postgresql.org/gitweb?p=pgpool2.git;a=commitdiff;h=e3f5da768eb853bce926016145587512939b6c7e

Modified Files
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doc.ja/src/sgml/release-3.7.sgml | 117 ++++++++++++++++++++
doc.ja/src/sgml/release-4.0.sgml | 212 ++++++++++++++++++++++++++++++++++++
doc/src/sgml/release-3.7.sgml    | 123 +++++++++++++++++++++
doc/src/sgml/release-4.0.sgml    | 224 +++++++++++++++++++++++++++++++++++++++
4 files changed, 676 insertions(+)