pgsql: Release notes for 10.1, 9.6.6, 9.5.10, 9.4.15, 9.3.20, 9.2.24.

Release notes for 10.1, 9.6.6, 9.5.10, 9.4.15, 9.3.20, 9.2.24.

In the v10 branch, also back-patch the effects of 1ff01b390 and c29c57890
on these files, to reduce future maintenance issues. (I'd do it further
back, except that the 9.X branches differ anyway due to xlog-to-wal
link tag renaming.)

Branch
------
master

Details
-------
https://git.postgresql.org/pg/commitdiff/b35b185bf705c4dbaf21198c81b3d85f4a96804a

Modified Files
--------------
doc/src/sgml/release-10.sgml | 253 ++-------------------
doc/src/sgml/release-9.2.sgml | 176 +++++++++++++++
doc/src/sgml/release-9.3.sgml | 192 ++++++++++++++++
doc/src/sgml/release-9.4.sgml | 236 ++++++++++++++++++++
doc/src/sgml/release-9.5.sgml | 288 ++++++++++++++++++++++++
doc/src/sgml/release-9.6.sgml | 506 ++++++++++++++++++++++++++++++++++++++++++
6 files changed, 1412 insertions(+), 239 deletions(-)