bootstrap: sync with upstream.

* bootstrap: Use the latest upstream version with better portability
to OpenBSD, and CLI compatibility with the GNU bootstrap script.

Signed-off-by: Gary V. Vaughan <gary@gnu.org>
specs: speed up most slow tests by three orders of magnitude.

* specs/mkrockspecs_spec.yaml: The gnulib tree is huge and
deep, so using os.execute to traverse all of it with subshells
is incredibly slow.  Only the last spec needs it, the rest are
much improved by putting the test fils in a subdirectory and
traversing only that.

Signed-off-by: Gary V. Vaughan <gary@gnu.org>
mkrockspecs: speed up mkrockspecs when luaposix is available.

* src/mkrockspecs.in (tree): Prefer a much faster implementation
when luaposix is available.

Signed-off-by: Gary V. Vaughan <gary@gnu.org>
configury: keep gnulib revision under version control.

* .gitignore: Add .gitmodules.
* gnulib: Add current master revision.

Signed-off-by: Gary V. Vaughan <gary@gnu.org>
configury: bump release version to 4.

* configure.ac (AC_INIT): Bump release version to 4.

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

* NEWS: Update with user visible changes since the last release.

Signed-off-by: Gary V. Vaughan <gary@gnu.org>
maint: patch corrupted old_NEWS_hash.

* local.mk (old_NEWS_hash): Regenerate.

Signed-off-by: Gary V. Vaughan <gary@gnu.org>
Release version 4

* NEWS: Record release date.
maint: post-release administrivia.

* NEWS: Add header line for next release.
* .prev-version: Record previous version.
* ./local.mk (old_NEWS_hash): Auto-update.

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