Hidden blog page is displayed in the list of "all blogs"

For BLOG-95, a panel to list all blogs was added.
However, hidden blog pages are also displayed as blogs in this panel, regardless of the settings of the current user.

This is particularily annoying if one wants to create a blog template page, there is simply no way to make this page not get displayed in the list there.

Also, the hidden blog is also displayed in the blog panels configuration added for BLOG-113 .