configury: add rockspec machinery.

* specl-rockspec.lua: New file. Rockspec data.
* build-aux/mkrockspecs.lua: New file. Reuben's templating
rockspec building script.
* GNUmakefile (luarocks-config.lua, rockspecs): Use it to build
rockspecs.
* src/specl.mk (EXTRA_DIST): Add build-aux/mkrockspecs.lua.

Signed-off-by: Gary V. Vaughan <gary@gnu.org>
configury: install correctly from './configure; make all install'.

The latest 'm4/ax_lua.m4' sets up pkgluadir to point into Lua's
module directory.
* Makefile.am (install_edit, inplace_edit): Remove useless
@pkgdatadir@ and @pkgdocdir@ substitutions.
* src/specl.mk (specldatadir): Remove.
(specl_install_edit, specl_inplace_edit): Use pkgluadir instead.
(dist_specldata_DATA): Rename from this...
(dist_pkglua_DATA): ...to this.
* src/specl.in (package.path): Inject pkgluadir substitution.
(PATH_DATA, PATH_DOCDIR): Remove.  Unused variables.

Signed-off-by: Gary V. Vaughan <gary@gnu.org>
maint: fix typos in GNUmakefile.

* GNUmakefile (unpack-distcheck-release): Add missing \s, ` and '.
(Makefile.in): Only one '-' in '-Wall'.

Signed-off-by: Gary V. Vaughan <gary@gnu.org>
specl: update to cleaner stdlib-33 getopt formats.

* src/version.lua.in (M.COPYRIGHT_NOTICE): Remove stray '\n'.
* src/specl.in (prog): No longer needs to be a magic global.
(options): Ditto.  Move from here...
(prog.options): ...to here.
(prog.purpose, prog.description): Reword to match rockspec.
(prog.version): Add this for --version output.
(prog.banner): Remove.

Signed-off-by: Gary V. Vaughan <gary@gnu.org>
maint: don't check release tarball file in on release branch.

* .gitignore: Ignore specl-*.tar.gz.
* build-aux/.gitignore: Don't ignore manually imported
gitlog-to-changelog.

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