Introduce AJAX response message

[alexvorn2]

when clicking on Save button of a widget, a error should appear if the user is logged out.

So after clicking the button the wpspin animated images disappears and nothing happens. This can be a problem if the current user think he is logged in and he is not, the settings just will not be saved.

Sometimes the server is not working.

Need to adjust the javascript code and php:
in php we can use die function : die('1') or die('success');

in javascript something like this:

$.post(ajaxurl, data, function(response){
   if (response === 'success') {} else { alert('Fail to save'); } 
});

​http://wpimpact.com/wp-content/uploads/2012/05/Untitled-4.png

Replace widget controls with "You are logged out!" message

This needs a look by one of the UX engineers, but I think the ticket raises a valid question. WordPress alerts when a draft can't be saved because a user is logged out, shouldn't widgets follow the same pattern? 20770.patch​ replaces the controls with a "You are logged out!" message. The message needs some padding (UI, help?) but it works.