[pgpool-committers: 5471] pgpool: Add release-notes 3.6.15-3.4.22.

[Bo Peng]

Add release-notes 3.6.15-3.4.22.

Branch
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V3_6_STABLE

Details
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https://git.postgresql.org/gitweb?p=pgpool2.git;a=commitdiff;h=2af405ea56aca1159f2f140bb1d919c3fae65823

Modified Files
--------------
doc.ja/src/sgml/release-3.4.sgml |  86 +++++++++++++++++++++
doc.ja/src/sgml/release-3.5.sgml | 113 +++++++++++++++++++++++++++
doc.ja/src/sgml/release-3.6.sgml | 160 +++++++++++++++++++++++++++++++++++++++
doc/src/sgml/release-3.4.sgml    |  63 +++++++++++++++
doc/src/sgml/release-3.5.sgml    |  84 ++++++++++++++++++++
doc/src/sgml/release-3.6.sgml    | 116 ++++++++++++++++++++++++++++
6 files changed, 622 insertions(+)