Add "Favorites" feature for Themes

[mario-siteground]

Currently there is a working functionality for plugins to mark plugins as favorite. It is helpful whenever you want to keep a track on decent themes to switch to for new websites.

Furthermore, this could be expanded to:

1) Implementing "Favorites" functionality itself on a low-level (code functionality needed)
2) Add UI for logged in users to mark themes as favorite
3) Add a list of favorite themes in a user's profile
4) Implement an extra tab in WordPress (the core) to allow for WordPress admin users to install favorite themes from within the admin panel.

[coffee2code]

#910 was marked as a duplicate.

[netweb]

Theme favourites were added in r1770, that fixes items 1 and 2 on this list.

[coffee2code]

Item 3 (add favorite themes to user profiles) has been implemented in [10716-dotorg] and [10717-dotorg].

Unmentioned in the original list but that has also been implemented by @dd32 is a "My Favorites" view that lists the logged-in user's favorite themes from within the Theme Directory.

I'm marking the ticket as fixed since the theme favorites feature has been implemented.

The final item of the original request (tab in WP core to install favorite themes) should be raised as a ticket on core.trac. The required API changes can be raised as a separate ticket here or just done in conjunction with the coordinated effort for the core changes (the API is at least partially there already).

[dd32]

In 1813:

Theme Directory: Switch the string 'My Favorites' out for a more consistent 'Favorites' used by the Plugins Directory & WordPress.
See #28

[ramiy]

Related: #1146