Provide A "Access Offline Site" Permission

After helping someone on the support@drupal.org mail list, I remembered I been wanting to raise this issue. Currently the only ones able to access the site in offline mode are those with the "administer site configuration" permission. This worked great for years, but in a world of telecommuting it does pose problems, especially on newly created sites. Namely, you might be training a bunch of people not used to Drupal, located around the world, accessing your site. In order for them to have access, they need that permission, which now adds in a bunch of new menu items and poses a huge UX problem when dealing with people that are nothing more than content authors and editors.

Changing the site offline access check to use a new permission (or even this permission on top of the administer site configuration) would allow the people being trained and setting up content on a new site, to be working on a site that will be the same when they go live.

IMHO this is a pretty serious usability problem that is very simple to correct and it would be great if we could get it into D8. If we go with a new permission, plus keeping access to those with "administer site configuration", then there would be no breaking in backwards compatibility, nor any need to alter existing roles and permissions in the database.