Allow wp_list_bookmarks() to show images AND names

[Otto42]

wp_list_bookmarks has a fairly serious shortcoming in that it cannot display both the image and the name of a given Link item, only one or the other. This is rather annoying when I want to show icons along with a name, like when showing links to other profiles of mine on various services (flickr, facebook, twitter, etc).

It would be nice if showing the name was an option, just as showing the images is. To this end, I added a "show_name" option to the _walk_bookmarks function, which functions similarly to the show_images option.

Patch attached.

Add show_name option to wp_list_bookmarks capabilities.

(In [9139]) Add show_name to wp_list_bookmarks(). Props Otto42. fixes #7847