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
Widget Customizer: Improve plugin compatibility.

Some plugins are using custom scripts and styles for there widgets. These are available on the Widgets screens, but not in the Customizer yet.
Scripts and styles can be enqueued via: 
* `admin_enqueue_scripts`
* `admin_print_scripts` and `admin_print_scripts-widgets.php`
* `admin_print_styles` and `admin_print_styles-widgets.php`
* `admin_print_footer_scripts` and `admin_footer-widgets.php`
All this hooks are now called in the Customizer too.

Previously we have add the `#widgets-right` ID to a container div via jQuery. Remember: `#widgets-right` exists on the Widgets screen and is used by many plugins to do event delegation from that element.
But since our script files are loaded in the footer, the JavaScript way is a bit late for some plugins.
We have decided to add a `div#widgets-right` container element to customizer. "Less hacky hack."

props westonruter, ocean90. Thanks dpe415 for testing.
fixes #27619.

git-svn-id: https://develop.svn.wordpress.org/trunk@27907 602fd350-edb4-49c9-b593-d223f7449a82
Fix a regression caused by [27622] in `prepend_attachment()` by passing all attachments that are not audio or video to the `else` clause.

Fixes #27634.



git-svn-id: https://develop.svn.wordpress.org/trunk@27908 602fd350-edb4-49c9-b593-d223f7449a82
Widget Customizer: Improve support for dynamically-created inputs.

* Re-work how and when widget forms get updated.
* Replace ad hoc hooks system with jQuery events,
* Add `widget-updated`/`widget-synced` events for widget soft/hard updates.
* Enter into a non-live form update mode, where the Apply button is restored when a sanitized form does not have the same fields as currently in the form, and so the fields cannot be easily updated to their sanitized values without doing a complete form replacement. Also restores live update mode if sanitized fields are aligned with the existing fields again.

Note: jQuery events are *not* final yet, see #19675.

props westonruter.
see #27491.

git-svn-id: https://develop.svn.wordpress.org/trunk@27909 602fd350-edb4-49c9-b593-d223f7449a82
Widget Customizer: Remove leading underscores from public methods.

Fix also an incorrect hook name in `stop_capturing_option_updates()`.

props DrewAPicture.
see #27534.

git-svn-id: https://develop.svn.wordpress.org/trunk@27910 602fd350-edb4-49c9-b593-d223f7449a82
Update suggest.min.js for [26333].

see #26110, #27599.
fixes #27621.

git-svn-id: https://develop.svn.wordpress.org/trunk@27911 602fd350-edb4-49c9-b593-d223f7449a82
Widget Customizer: Don't use opacity for the update spinner.

`opacity` isn't supported in IE8 and makes the spinner always visible.

see #27485.

git-svn-id: https://develop.svn.wordpress.org/trunk@27912 602fd350-edb4-49c9-b593-d223f7449a82
Widget Customizer: Restore deferral of `previewer-loading` class removal until preview is synced.

props westonruter.
fixes #27635.

git-svn-id: https://develop.svn.wordpress.org/trunk@27913 602fd350-edb4-49c9-b593-d223f7449a82
Remove <br> elements for HTML5 galleries.

props obenland.
fixes #27637, see #26697.


git-svn-id: https://develop.svn.wordpress.org/trunk@27914 602fd350-edb4-49c9-b593-d223f7449a82
Fix copy/paste error in [27710].

props kovshenin.
fixes #21969.

git-svn-id: https://develop.svn.wordpress.org/trunk@27915 602fd350-edb4-49c9-b593-d223f7449a82