[pgpool-committers: 7740] pgpool: Add release notes.

[Bo Peng]

Add release notes.

Branch
------
V4_0_STABLE

Details
-------
https://git.postgresql.org/gitweb?p=pgpool2.git;a=commitdiff;h=08198cf7064f9dadd55b72b98c56d16dc03516ed

Modified Files
--------------
doc.ja/src/sgml/release-3.6.sgml | 80 ++++++++++++++++++++++++++++++++
doc.ja/src/sgml/release-3.7.sgml | 89 ++++++++++++++++++++++++++++++++++++
doc.ja/src/sgml/release-4.0.sgml | 99 ++++++++++++++++++++++++++++++++++++++++
doc.ja/src/sgml/version.sgml     |  2 +-
doc/src/sgml/release-3.6.sgml    | 71 ++++++++++++++++++++++++++++
doc/src/sgml/release-3.7.sgml    | 80 ++++++++++++++++++++++++++++++++
doc/src/sgml/release-4.0.sgml    | 90 ++++++++++++++++++++++++++++++++++++
doc/src/sgml/version.sgml        |  2 +-
8 files changed, 511 insertions(+), 2 deletions(-)