Add index.php

Based on appearence configuration the user is redirected to login.php when usenewui is set to true,
or to frontpage_welcome.php for the default design.

www/index.php

@@ -2,4 +2,10 @@
 
 require_once('_include.php');
 
-\SimpleSAML\Utils\HTTP::redirectTrustedURL(SimpleSAML\Module::getModuleURL('core/frontpage_welcome.php'));
+$config = SimpleSAML_Configuration::getInstance();
+
+if ($config->getBoolean('usenewui', false)) {
+    \SimpleSAML\Utils\HTTP::redirectTrustedURL(SimpleSAML\Module::getModuleURL('core/login.php'));
+}
+
+    \SimpleSAML\Utils\HTTP::redirectTrustedURL(SimpleSAML\Module::getModuleURL('core/frontpage_welcome.php'));