NEWS updates for 1.6.2

Add an entry for 1.6.2 with "in progress" instead of a date to hold the
release notes for 1.6.2pre4 rather than creating separate entries for
each release candidate. Users who track the release candidates can refer
to the public announcements, and this will be cleaner when reading
history later on.

Reviewed-on: http://gerrit.openafs.org/8750
Reviewed-by: Ken Dreyer <ktdreyer@ktdreyer.com>
Tested-by: Ken Dreyer <ktdreyer@ktdreyer.com>
(cherry picked from commit 265a4b542b717c14e810202078c3ce83e4d851f5)

Change-Id: I68d4e6983097a97caac660f740ea8a01f1a95caa
Reviewed-on: http://gerrit.openafs.org/8988
Reviewed-by: Ken Dreyer <ktdreyer@ktdreyer.com>
Reviewed-by: Stephan Wiesand <stephan.wiesand@desy.de>
Tested-by: BuildBot <buildbot@rampaginggeek.com>
Reviewed-by: Paul Smeddle <paul.smeddle@gmail.com>