changing SiteManager to use ConcurrentDictionary and ConcurrentQueue. Fixing some race conditions and some null refs
Sending delete from the browser when the timer expires.
    This will give a more consistant UI experiance. The server will delete the site anyway, but it has a resolution of 1 minute
    So worst case senario is that it takes a minute longer. In that case the UI might get weird if the user tries to dismiss and create right away or refresh the page.
clicking on the 'work with your site' icons doesn't work sometimes, fixes #19