Make OpenAFS 1.6.10

Update version strings and NEWS for 1.6.10

Change-Id: Idc59095829a7b8a1f882b46d9228d524820fc6fc
Reviewed-on: http://gerrit.openafs.org/11486
Tested-by: BuildBot <buildbot@rampaginggeek.com>
Reviewed-by: Benjamin Kaduk <kaduk@mit.edu>
Reviewed-by: Michael Meffie <mmeffie@sinenomine.net>
Reviewed-by: Stephan Wiesand <stephan.wiesand@desy.de>