specl: automate specl support.

* configure.ac: Add SPECL path search and substition.
* build-aux/specl.mk: Rules to run specl tests.
* specs/specs.mk: Remove everything but the specs list.
* travis.yml: On Travis, SPECL is either the one we build into
bin/ otherwise we install the specl rock to luarocks/bin.
* .travis.yml: Regenerate.

Signed-off-by: Gary V. Vaughan <gary@gnu.org>
configury: remove ax_with_prog.m4.

* m4/ax_with_prog.m4: Remove.
* configure.ac: Use AC_PATH_PROG instead of AX_WITH_PROG.

Signed-off-by: Gary V. Vaughan <gary@gnu.org>
travis: set SPECL_FALSE for .travis.yml generation.

* configure.ac: set SPECL_FALSE for .travis.yml generation.

Signed-off-by: Gary V. Vaughan <gary@gnu.org>
maint: move old_NEWS_hash into local.mk.

* Makefile.am (old_NEWS_hash): Move from here...
* local.mk: New file. ...to here.
* build-aux/release.mk (old_NEWS_hash-file): Adjust.
(release_extra_dist): Add local.mk.

Signed-off-by: Gary V. Vaughan <gary@gnu.org>
release: redo announcements without mutt mail wrapper.

* build-aux/mail: Remove.
* build-aux/relase.mk (announcement): Reword.
(announce_emails, rockspec_emails): Overridable announcement
destination addresses.
(mail): Use system `mail` by sending rockspec url rather than
an attachment.
NEWS: Update.

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