[pgpool-committers: 4749] pgpool: Add release-notes 3.7.4 - 3.4.18.

[Bo Peng]

Add release-notes 3.7.4 - 3.4.18.

Branch
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V3_7_STABLE

Details
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https://git.postgresql.org/gitweb?p=pgpool2.git;a=commitdiff;h=6d7a12be7d9386b939ab681d7d68587e5f0d6afa

Modified Files
--------------
doc.ja/src/sgml/release-3.4.sgml |  57 ++++++++++++
doc.ja/src/sgml/release-3.5.sgml |  89 ++++++++++++++++++
doc.ja/src/sgml/release-3.6.sgml | 136 ++++++++++++++++++++++++++++
doc.ja/src/sgml/release-3.7.sgml | 189 +++++++++++++++++++++++++++++++++++++++
doc/src/sgml/release-3.4.sgml    |  35 ++++++++
doc/src/sgml/release-3.5.sgml    |  57 ++++++++++++
doc/src/sgml/release-3.6.sgml    |  94 +++++++++++++++++++
doc/src/sgml/release-3.7.sgml    | 130 +++++++++++++++++++++++++++
8 files changed, 787 insertions(+)