Redundant caps checks in wp_admin_bar_appearance_menu()

[duck_]

if ( ! current_user_can('switch_themes') && ! current_user_can( 'edit_theme_options' ) )
    return;

if ( ! current_user_can( 'edit_theme_options' ) )
    return;

The first set can just be removed.

However, I think that the correct behaviour would be to display "Themes" if the user has either switch_themes or edit_theme_options and only display the rest if they have edit_theme_options.

Related: [17741] and #15931; [19006], [19026] and #18197.

[nacin]

As wp_admin_bar_appearance_menu() had the parent removed, the cap checks can be simplified quite a bit.

[duck_]

In [19153]:

Fix caps logic in wp_admin_bar_appearance_menu(). Show Themes on either switch_themes or edit_theme_options, and the rest of the appearance items on edit_theme_options. Fixes #19150.