DocBook: Generate consistent IDs

By default, DocBook XSL uses a non-deterministic function to generate
IDs for HTML elements where it can't take a name from the input
document.  However, it has the option to generate 'consistent'
(deterministic) IDs instead.  Enable this to make the HTML pages
reproducible.
Reported-by: Jérémy Bobbio <lunar@debian.org>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>

Documentation/DocBook/stylesheet.xsl

@@ -5,6 +5,7 @@
 <param name="funcsynopsis.tabular.threshold">80</param>
 <param name="callout.graphics">0</param>
 <!-- <param name="paper.type">A4</param> -->
+<param name="generate.consistent.ids">1</param>
 <param name="generate.section.toc.level">2</param>
 <param name="use.id.as.filename">1</param>
 </stylesheet>