Ensure that a `has_children` parameter is given to `Walker::start_el()`.

Adds unit tests.

Props scribu, obenland.
Fixes #14041.

Built from https://develop.svn.wordpress.org/trunk@28824


git-svn-id: http://core.svn.wordpress.org/trunk@28628 1a063a9b-81f0-0310-95a4-ce76da25c4cd
Simplify the setting of `$args['include']` in `wp_get_nav_menu_items()`.

Props UmeshSingla.
Fixes #28515.

Built from https://develop.svn.wordpress.org/trunk@28825


git-svn-id: http://core.svn.wordpress.org/trunk@28629 1a063a9b-81f0-0310-95a4-ce76da25c4cd
When selecting a fallback menu in `wp_nav_menu()`, the "first" menu is retrieved from an unsorted query. When retrieving a fallback menu, pass `array( 'orderby' => 'name' )` to `wp_get_nav_menus()` to return a menu consistently.

Props lukecarbis.
Fixes #28126.

Built from https://develop.svn.wordpress.org/trunk@28826


git-svn-id: http://core.svn.wordpress.org/trunk@28630 1a063a9b-81f0-0310-95a4-ce76da25c4cd