doc update: add build system integration and project maturity to introduction

index.html

@@ -180,8 +180,13 @@
         whenever possible
     </li>
     <li>
-        is already
-        <a href="#used-by">used by several projects</a>
+        integrates well with <a href="#tutorial-5a">autotools</a>,
+        <a href="#tutorial-5b">cmake</a>, <a href="#tutorial-5c">qmake</a>,
+        and <a href="#tutorial-5d">hand-written makefiles</a>.
+    </li>
+    <li>
+        has been in continuous development <a href="#history">since 2007</a>
+        and is <a href="#used-by">used by several projects</a>
     </li>
     </ul>