Make `<audio>` elements in playlists responsive.

See #27625.



git-svn-id: https://develop.svn.wordpress.org/trunk@27894 602fd350-edb4-49c9-b593-d223f7449a82
Call MediaElement's shim method for `setSrc()` when dynamically updating the playing source in playlists, which will properly set the source for mobile.

Make the labels for playlist items slightly smaller to account for size on mobile.

Fixes #27625.



git-svn-id: https://develop.svn.wordpress.org/trunk@27895 602fd350-edb4-49c9-b593-d223f7449a82
Theme Installer fixes:
 * Better more filters section. props sonjanyc for some mockups.
 * Better handling of no results.
 * Use # for hrefs.

props matveb.
see #27055.


git-svn-id: https://develop.svn.wordpress.org/trunk@27896 602fd350-edb4-49c9-b593-d223f7449a82
TinyMCE: update to 4.0.21, see #24067

git-svn-id: https://develop.svn.wordpress.org/trunk@27897 602fd350-edb4-49c9-b593-d223f7449a82
Edit Image modal:
- Move all advanced options under a single “Show advanced options” toggle that mirrors the behavior and look-and-feel of the wplink modal.
- Switch to using <select> for the Size and Link To.
- Bring back the field for CSS Class for the image, but don’t incorporate the internally managed WordPress classes (size-, wp-image-, etc…).
- On larger screen sizes, float labels to the left. When the width drops below 900px, stack the label above the fields.
- Keep image at top on screen sizes where the two columns are stacked into a single column.
- Don't replace the nodes in the editor DOM so we don't stomp on any custom attributes that the user may have added via the Text editor or some other mechanism.
Props gcorne, see #27366

git-svn-id: https://develop.svn.wordpress.org/trunk@27898 602fd350-edb4-49c9-b593-d223f7449a82
Gallery preview: add a "No items found" state which is displayed when rendering the gallery wpview and no attachments are found. Props gcorne, fixes #27558

git-svn-id: https://develop.svn.wordpress.org/trunk@27899 602fd350-edb4-49c9-b593-d223f7449a82
wpLink: fix spinners selectors and add some throttling when searching with AJAX while the user is typing, fixes #27615

git-svn-id: https://develop.svn.wordpress.org/trunk@27900 602fd350-edb4-49c9-b593-d223f7449a82
Drag and drop files on the editor to upload: add new argument to wp_editor() to enable, fixes #27465

git-svn-id: https://develop.svn.wordpress.org/trunk@27901 602fd350-edb4-49c9-b593-d223f7449a82
Improve some inline documentation for class properties in `WP_Customize_Section`.

Props leewillis77 for the initial patch.
Fixes #26245.


git-svn-id: https://develop.svn.wordpress.org/trunk@27902 602fd350-edb4-49c9-b593-d223f7449a82
Second-pass inline documentation improvements for WP_Customize_Widgets.

See #27534.


git-svn-id: https://develop.svn.wordpress.org/trunk@27903 602fd350-edb4-49c9-b593-d223f7449a82
Coding standards and readability spacing for WP_Customize_Widgets.

Also explicitly re-mark `_capture_filter_pre_update_option()` and `_capture_filter_pre_get_option()` as public.

See #27534.


git-svn-id: https://develop.svn.wordpress.org/trunk@27904 602fd350-edb4-49c9-b593-d223f7449a82
Background Updates: Record Plugin & Theme update statistics like we for for Core updates, Pass Plugin/Theme update objects into the Background updater for consistency with Core & Translations. See #27633


git-svn-id: https://develop.svn.wordpress.org/trunk@27905 602fd350-edb4-49c9-b593-d223f7449a82
Background Updates: Fix two variable typos in r27905


git-svn-id: https://develop.svn.wordpress.org/trunk@27906 602fd350-edb4-49c9-b593-d223f7449a82