revision.c: explain what tree_difference does

diff --git a/Documentation/Makefile b/Documentation/Makefile
index b6d1d8824f39557495ed479c0823f66f792b51f6..7c1c9e1918829b90aeb4e47d10aa0f5951204b0c 100644 (file)
--- a/Documentation/Makefile
+++ b/Documentation/Makefile
@@ -105,8 +105,11 @@ clean:
 user-manual.xml: user-manual.txt user-manual.conf
        $(ASCIIDOC) -b docbook -d book $<
 
+XSLT = http://docbook.sourceforge.net/release/xsl/current/html/docbook.xsl
+XSLTOPTS = --nonet --xinclude --stringparam html.stylesheet docbook-xsl.css
+
 user-manual.html: user-manual.xml
-       xmlto html-nochunks $<
+       xsltproc $(XSLTOPTS) -o $@ $(XSLT) $<
 
 glossary.html : glossary.txt sort_glossary.pl
        cat $< | \