GSMaintenance: Put your site in "Maintenance mode"

[maf]

Hi, this can be usefull while setting up the site. One suggestion/wish: can you please add option to show the web even in maintenance mode for certain (configurable) IPs? Thus I could for example cooperate with customer on web creation on the final hosting server and set that me and the customer would see the site during creation, while the rest of world will see the maintenance notice until the web is ready.