Remove a duplicate semicolon that snuck in. Props JustinSainton. See #18200

Built from https://develop.svn.wordpress.org/trunk@25822


git-svn-id: http://core.svn.wordpress.org/trunk@25734 1a063a9b-81f0-0310-95a4-ce76da25c4cd
Make WP_Automatic_Upgrader a proper object that gets instantiated. Renames nearly all of its methods.

Also renames wp_auto_updates_maybe_update() to wp_maybe_auto_update().

see #22704.

Built from https://develop.svn.wordpress.org/trunk@25823


git-svn-id: http://core.svn.wordpress.org/trunk@25735 1a063a9b-81f0-0310-95a4-ce76da25c4cd