Added checks for admin permissions to settings / users.

Added welcome message and start page contents in input interface (iss0000160).

edit/users.php

@@ -17,6 +17,10 @@ $translations = loadLanguage(); // Load translations.
 ensureBackendEnv();             // Ensure session is started etc.
 $pages = loadPages();           // Load overview of pages.
 
+if (!$_SESSION['admin']) {
+    echo printErrorPage($translations['accessDenied']); return;
+}
+
 /*
  * Load data.
  */