aggregator2: add an index page that lists the available aggregates and links to them.

modules/aggregator2/templates/list.php

+<?php
+$this->includeAtTemplateBase('includes/header.php');
+?>
+    <h1><?php echo $this->t('{aggregator2:aggregator:header}'); ?></h1>
+
+<?php
+if (count($this->data['sources']) === 0) {
+    echo "    <p>".$this->t('{aggregator2:aggregator:no_aggregators}')."</p>\n";
+} else {
+    echo "    <ul>";
+
+    foreach ($this->data['sources'] as $id => $source) {
+        $encId = urlencode($id);
+        $params = array(
+            'id' => $encId,
+        );
+        echo str_repeat(' ', 8)."<li>\n";
+        echo str_repeat(' ', 12).'<a href="';
+        echo SimpleSAML_Module::getModuleURL('aggregator2/get.php', $params).'">'.htmlspecialchars($id)."</a>\n";
+        echo str_repeat(' ', 12).'<a href="';
+        $params['mimetype'] = 'text/plain';
+        echo SimpleSAML_Module::getModuleURL('aggregator2/get.php', $params).'">['.
+            $this->t('{aggregator2:aggregator:text}')."]</a>\n";
+        echo str_repeat(' ', 12).'<a href="';
+        $params['mimetype'] = 'application/xml';
+        echo SimpleSAML_Module::getModuleURL('aggregator2/get.php', $params)."\">[XML]</a>\n";
+        echo str_repeat(' ', 8)."</li>\n";
+    }
+
+    echo "    </ul>\n";
+}
+
+$this->includeAtTemplateBase('includes/footer.php');

modules/aggregator2/www/index.php

+<?php
+
+$ssp_cf = SimpleSAML_Configuration::getInstance();
+$mod_cf = SimpleSAML_Configuration::getConfig('module_aggregator2.php');
+
+// get list of sources
+$sources = $mod_cf->toArray();
+
+$t = new SimpleSAML_XHTML_Template($ssp_cf, 'aggregator2:list.php');
+$t->data['sources'] = $sources;
+$t->show();