Release version 1.4.17

* gnulib: Update to lastest for assorted OS X fixes.
* NEWS: Set the release date.

Signed-off-by: Gary V. Vaughan <gary@gnu.org>
maint: post-release administrivia

* NEWS: Add header line for next release.
* .prev-version: Record previous version.
* cfg.mk (old_NEWS_hash): Auto-update.
maint: update HACKING release instructions.

* HACKING: Update release instructions.

Signed-off-by: Gary V. Vaughan <gary@gnu.org>