Access class directly instead of using `this` in the `shortcodeAttrs` method of any factory-generated `wp.media.collection`.

Fixes #27183.


Built from https://develop.svn.wordpress.org/trunk@27238


git-svn-id: http://core.svn.wordpress.org/trunk@27095 1a063a9b-81f0-0310-95a4-ce76da25c4cd
Add core support for Playlists and Video Playlists.

* Playlists operate like galleries in the admin. 
* Provide default UI and JS support in themes using MediaElement and Backbone. 
* The shortcodes are clickable, editable, and configurable using the media modal. 
* Playlists support images for each item, whether or not the current theme supports images for `attachment:audio` and `attachment:video`
* Playlists respond to `$content_width` and resize videos accordingly.
* All playlist data is included inline, using a script tag with `type="application/json"`, allowing anyone to unenqueue the WP playlist JS and roll their own.
* Playlist styles are minimal and work out of the box in the last 5 default themes. They inherit and adapt to the current theme's font styles, and their rules are easily overrideable.

See #26631.


Built from https://develop.svn.wordpress.org/trunk@27239


git-svn-id: http://core.svn.wordpress.org/trunk@27096 1a063a9b-81f0-0310-95a4-ce76da25c4cd
Inline documentation improvements for `wp_get_playlist()`.

* Adds a missing `@param` description in the PHPDoc.
* Adds hook documentation for the `post_playlist` filter.
* Other comment cleanup.

Built from https://develop.svn.wordpress.org/trunk@27240


git-svn-id: http://core.svn.wordpress.org/trunk@27097 1a063a9b-81f0-0310-95a4-ce76da25c4cd
Spacing fixes for code introduced in [27239].

See #26631

Built from https://develop.svn.wordpress.org/trunk@27241


git-svn-id: http://core.svn.wordpress.org/trunk@27098 1a063a9b-81f0-0310-95a4-ce76da25c4cd
Load default settings state when creating a new playlist in the media modal. Add a few missing inline `@this` annotations in `media-editor.js`.

See #26631.


Built from https://develop.svn.wordpress.org/trunk@27242


git-svn-id: http://core.svn.wordpress.org/trunk@27099 1a063a9b-81f0-0310-95a4-ce76da25c4cd
Remove a few unnecessary jQuery selectors added in [27239]. Playlists don't exist in some older contexts that galleries do.

See #26631.


Built from https://develop.svn.wordpress.org/trunk@27243


git-svn-id: http://core.svn.wordpress.org/trunk@27100 1a063a9b-81f0-0310-95a4-ce76da25c4cd
Supply mime-type instead of extension for an item's `type` property in playlist JSON.

See #26631.


Built from https://develop.svn.wordpress.org/trunk@27244


git-svn-id: http://core.svn.wordpress.org/trunk@27101 1a063a9b-81f0-0310-95a4-ce76da25c4cd
Get the proper image size for an item's thumb in playlist JSON.

See #26631.


Built from https://develop.svn.wordpress.org/trunk@27245


git-svn-id: http://core.svn.wordpress.org/trunk@27102 1a063a9b-81f0-0310-95a4-ce76da25c4cd
Add Oxford comma to password hint.

props trepmal.
fixes #26457.
Built from https://develop.svn.wordpress.org/trunk@27246


git-svn-id: http://core.svn.wordpress.org/trunk@27103 1a063a9b-81f0-0310-95a4-ce76da25c4cd
Fix theme preview URL for themes loaded via AJAX on Install Themes screen.

props ocean90.
fixes #27128.
Built from https://develop.svn.wordpress.org/trunk@27247


git-svn-id: http://core.svn.wordpress.org/trunk@27104 1a063a9b-81f0-0310-95a4-ce76da25c4cd
Fix thickbox positioning if toolbar is not present.

fixes #26745.
Built from https://develop.svn.wordpress.org/trunk@27248


git-svn-id: http://core.svn.wordpress.org/trunk@27105 1a063a9b-81f0-0310-95a4-ce76da25c4cd
Declare $wpdb->base_prefix.

props DavidAnderson.
fixes #16762.

Built from https://develop.svn.wordpress.org/trunk@27249


git-svn-id: http://core.svn.wordpress.org/trunk@27106 1a063a9b-81f0-0310-95a4-ce76da25c4cd
Use ext/mysqli in PHP 5.5 or greater. Expect minor explosions.

props aaroncampbell, pento.
see #21663.

Built from https://develop.svn.wordpress.org/trunk@27250


git-svn-id: http://core.svn.wordpress.org/trunk@27107 1a063a9b-81f0-0310-95a4-ce76da25c4cd
Consistently return a WP_Error object in case of an error in wp_update_nav_menu_item().

props bootsz, ocean90.
fixes #21652.
Built from https://develop.svn.wordpress.org/trunk@27251


git-svn-id: http://core.svn.wordpress.org/trunk@27108 1a063a9b-81f0-0310-95a4-ce76da25c4cd
Prevent large images in comments from overflowing the meta box.

props mattheu.
fixes #26643.
Built from https://develop.svn.wordpress.org/trunk@27252


git-svn-id: http://core.svn.wordpress.org/trunk@27109 1a063a9b-81f0-0310-95a4-ce76da25c4cd
Force UTF-8 in load-styles.php, like we do in load-scripts.php.

props iamfriendly, mjbanks.
fixes #25012.
Built from https://develop.svn.wordpress.org/trunk@27253


git-svn-id: http://core.svn.wordpress.org/trunk@27110 1a063a9b-81f0-0310-95a4-ce76da25c4cd
Fix the tags input in small viewports and make it a more reasonable size. props SergeyBiryukov. fixes #27082.

Built from https://develop.svn.wordpress.org/trunk@27254


git-svn-id: http://core.svn.wordpress.org/trunk@27111 1a063a9b-81f0-0310-95a4-ce76da25c4cd
Inline documentation for hooks in wp-admin/includes/class-wp-posts-list-table.php.

Props nicolealleyinteractivecom, kpdesign.
Fixes #26397.

Built from https://develop.svn.wordpress.org/trunk@27255


git-svn-id: http://core.svn.wordpress.org/trunk@27112 1a063a9b-81f0-0310-95a4-ce76da25c4cd
Inline documentation for hooks in wp-admin/includes/screen.php.

Props enej, kpdesign.
Fixes #26821.

Built from https://develop.svn.wordpress.org/trunk@27256


git-svn-id: http://core.svn.wordpress.org/trunk@27113 1a063a9b-81f0-0310-95a4-ce76da25c4cd