update Piwik to version 2.16 (fixes #91)

www/analytics/plugins/Monolog/config/tracker.php

@@ -0,0 +1,37 @@
+<?php
+
+use Interop\Container\ContainerInterface;
+
+function isTrackerDebugEnabled(ContainerInterface $c)
+{
+    $trackerDebug = $c->get("ini.Tracker.debug");
+    return ($trackerDebug == 1 || !empty($GLOBALS['PIWIK_TRACKER_DEBUG']));
+}
+
+return array(
+
+    'Psr\Log\LoggerInterface' => function (ContainerInterface $c) {
+        if (isTrackerDebugEnabled($c)) {
+            return $c->get('Monolog\Logger');
+        } else {
+            return new \Psr\Log\NullLogger();
+        }
+    },
+
+    'log.handler.classes' => DI\decorate(function ($previous) {
+        if (isset($previous['screen'])) {
+            $previous['screen'] = 'Piwik\Plugins\Monolog\Handler\EchoHandler';
+        }
+
+        return $previous;
+    }),
+
+    'log.level' => DI\decorate(function ($previous, ContainerInterface $c) {
+        if (isTrackerDebugEnabled($c)) {
+            return \Monolog\Logger::DEBUG;
+        }
+
+        return $previous;
+    })
+
+);