org: replace version references with org-babel blocks

This way we have fewer lines to edit multiple when making releases.

* doc/org/index.org, doc/org/init.el.in, doc/org/install.org,
doc/org/setup.org, doc/org/tools.org: Use org-babel instead of macros
for release version and links.

doc/org/index.org

@@ -37,7 +37,7 @@ checking.  It has the following notable features:
 
 * Latest version
 
-The latest version is *{{{LASTRELEASE}}}* and was released on
+The latest version is *call_SPOT_VERSION()* and was released on
 *{{{LASTDATE}}}*.  Please see the [[file:install.org][download and installation instructions]].
 
 * Documentation

doc/org/init.el.in

@@ -160,7 +160,7 @@ up.html points to index.html, then the result is:
           (setq body res)
           (not cmp)))
     (concat "#+TITLE: " title
-            "\n#+SETUPFILE: setup.org\n#+HTML_LINK_UP: index.html\n\n"
+            "\n#+INCLUDE: setup.org\n#+HTML_LINK_UP: index.html\n\n"
             body)))
 
 (setq org-publish-project-alist

doc/org/install.org

@@ -9,9 +9,9 @@
    :CUSTOM_ID: tar
    :END:
 
-The latest release of Spot is version {{{LASTRELEASE}}}:
+The latest release of Spot is version call_SPOT_VERSION() and was released on {{{LASTDATE}}}:
 
-- {{{LASTTARBALL}}} (see also the {{{LASTNEWS}}})
+- call_TARBALL_LINK() (see also the call_NEWS_LINK())
 
 Past releases can be found [[https://www.lrde.epita.fr/dload/spot/][in the same directory]].  If you are
 interested in /future/ releases, you can always peek at the [[https://gitlab.lre.epita.fr/spot/spot/-/jobs/artifacts/next/browse?job=make-dist][last

doc/org/setup.org

@@ -1,11 +1,23 @@
 #+OPTIONS: H:2 num:nil toc:t html-postamble:nil ^:nil
 #+EMAIL: spot@lrde.epita.fr
 #+HTML_LINK_HOME: index.html
-#+MACRO: SPOTVERSION 2.11.4
-#+MACRO: LASTRELEASE 2.11.4
-#+MACRO: LASTTARBALL [[http://www.lrde.epita.fr/dload/spot/spot-2.11.3.tar.gz][=spot-2.11.4.tar.gz=]]
-#+MACRO: LASTNEWS [[https://gitlab.lre.epita.fr/spot/spot/blob/spot-2-11-3/NEWS][summary of the changes]]
 #+MACRO: LASTDATE 2023-02-10
 
+#+NAME: SPOT_VERSION
+#+BEGIN_SRC python :exports none :results value :wrap org
+return "2.11.4"
+#+END_SRC
+
+#+NAME: TARBALL_LINK
+#+BEGIN_SRC python :exports none :var version=SPOT_VERSION :results output :wrap org
+  print(f"[[http://www.lrde.epita.fr/dload/spot/spot-{version}.tar.gz][=spot-{version}.tar.gz=]]")
+#+END_SRC
+
+#+NAME: NEWS_LINK
+#+BEGIN_SRC python :exports none :var version=SPOT_VERSION :results output :wrap org
+  version = version.replace('.', '-')
+  print(f"[[https://gitlab.lre.epita.fr/spot/spot/blob/spot-{version}/NEWS][summary of the changes]]")
+#+END_SRC
+
 #+ATTR_HTML: :id spotlogo
 [[file:spot2.svg]]

doc/org/tools.org

@@ -1,12 +1,12 @@
 # -*- coding: utf-8 -*-
-#+TITLE: Command-line tools installed by Spot {{{SPOTVERSION}}}
-#+DESCRIPTION: List of all the command-line tools installed by Spot {{{SPOTVERSION}}}
 #+INCLUDE: setup.org
+#+TITLE: Command-line tools installed by Spot
+#+DESCRIPTION: List of all the command-line tools installed by Spot
 #+HTML_LINK_UP: index.html
 #+PROPERTY: header-args:sh :results verbatim :exports both
 
 This document introduces command-line tools that are installed with
-the Spot library.  We give some examples to highlight possible
+Spot call_SPOT_VERSION().  We give some examples to highlight possible
 use-cases but shall not attempt to cover all features exhaustively
 (please check the man pages for further inspiration).