Add initial support for CSRF token protection

tailbone/templates/login.mako

@@ -17,6 +17,7 @@
   <div class="form">
     ${form.begin(**{'data-ajax': 'false'})}
     ${form.hidden('referrer', value=referrer)}
+    ${form.csrf_token()}
 
     ${form.field_div('username', form.text('username'))}
     ${form.field_div('password', form.password('password'))}