[Doc] Remove tracker

doc/footer.html

@@ -17,20 +17,5 @@ $generatedby &#160;<a href="http://www.doxygen.org/index.html">
 </small></address>
 <!--END !GENERATE_TREEVIEW-->
 
-<!-- Piwik -->
-<script type="text/javascript">
-var pkBaseURL = (("https:" == document.location.protocol) ? "https://stats.sylphide-consulting.com/piwik/" : "http://stats.sylphide-consulting.com/piwik/");
-document.write(unescape("%3Cscript src='" + pkBaseURL + "piwik.js' type='text/javascript'%3E%3C/script%3E"));
-</script><script type="text/javascript">
-try {
-var piwikTracker = Piwik.getTracker(pkBaseURL + "piwik.php", 20);
-piwikTracker.trackPageView();
-piwikTracker.enableLinkTracking();
-} catch( err ) {}
-</script><noscript><p><img src="http://stats.sylphide-consulting.com/piwik/piwik.php?idsite=20" style="border:0" alt="" /></p></noscript>
-<!-- End Piwik Tracking Code -->
-
 </body>
 </html>
-
-