add cache_logins* options

config

@@ -62,6 +62,12 @@
 # Value: none | htpasswd | remote_user | http_x_remote_user | ldap | denyall
 #type = none
 
+# Cache successful logins for until expiration time
+#cache_logins = false
+
+# Expiration time for caching successful logins in seconds
+#cache_logins_expiry = 5
+
 # URI to the LDAP server
 #ldap_uri = ldap://localhost