Switch to side-by-side view

--- a/doc/building.html
+++ b/doc/building.html
@@ -762,8 +762,8 @@
 </li>
 <li>
 <p>
-Only for building from git source: the autotools (autoconf, automake,
-  libtool).
+Only for building from git source, and for libupnpp: the autotools
+  (autoconf, automake, libtool).
 </p>
 </li>
 </ul></div>
@@ -865,7 +865,7 @@
 <div id="footer">
 <div id="footer-text">
 Last updated
- 2018-06-14 05:15:38 CEST
+ 2018-11-14 08:37:29 CET
 </div>
 </div>
 </body>