In `WP_Meta_Query`, interpret 'value' correctly when used with EXISTS/NOT EXISTS.

As in earlier versions, EXISTS with a value is equivalent to '=', while NOT
EXISTS should always ignore 'value'.

Props barrykooij.
Fixes #30681 for trunk.

git-svn-id: https://develop.svn.wordpress.org/trunk@30846 602fd350-edb4-49c9-b593-d223f7449a82
Customizer: Don't escape control descriptions in JavaScript templates.

fixes #30682 for trunk.

git-svn-id: https://develop.svn.wordpress.org/trunk@30847 602fd350-edb4-49c9-b593-d223f7449a82
Customizer: Re-add the possibility to remove and restore a default background image.

see #21483.
fixes #30683 for trunk.

git-svn-id: https://develop.svn.wordpress.org/trunk@30849 602fd350-edb4-49c9-b593-d223f7449a82
Improve the fix for menu shakiness when over-scrolling. Recalculate heights on editor auto-resize.
See #30692.

git-svn-id: https://develop.svn.wordpress.org/trunk@30852 602fd350-edb4-49c9-b593-d223f7449a82
Editor, new DFW: fix fading out for the right sidebar in IE. Fixes #30714.

git-svn-id: https://develop.svn.wordpress.org/trunk@30853 602fd350-edb4-49c9-b593-d223f7449a82
Avoid repeatedly calling is_tax( 'post_format', '...' ) in get_the_archive_title().

see #21995.


git-svn-id: https://develop.svn.wordpress.org/trunk@30854 602fd350-edb4-49c9-b593-d223f7449a82
No need for wp_get_password_hint() to be prefixed as if it is private.

see #21243.


git-svn-id: https://develop.svn.wordpress.org/trunk@30855 602fd350-edb4-49c9-b593-d223f7449a82
Rename _wp_clear_update_cache() to wp_clean_update_cache().

This makes it match most cache-clearing functions, including the ones it wraps. Also no need for it to be prefixed as "private."

wp_clean_plugins_cache() doesn't always exist, so as a quick fix, clear the transient we care to clear.

see #30369.


git-svn-id: https://develop.svn.wordpress.org/trunk@30856 602fd350-edb4-49c9-b593-d223f7449a82
About page design for 4.1.

props melchoyce and ryelle, who again outdid themselves.
see #30435.


git-svn-id: https://develop.svn.wordpress.org/trunk@30857 602fd350-edb4-49c9-b593-d223f7449a82
Background Updates: Pass back whether Group Writable support is being leveraged for an update to the WordPress.org API.
See #30245


git-svn-id: https://develop.svn.wordpress.org/trunk@30860 602fd350-edb4-49c9-b593-d223f7449a82
Twenty Fifteen: remove Genericons as a dependency from loading the main stylesheet.

Props iamtakashi, fixes #30532.

git-svn-id: https://develop.svn.wordpress.org/trunk@30865 602fd350-edb4-49c9-b593-d223f7449a82
Twenty Fourteen: remove Genericons as a dependency from loading the main stylesheet and IE-specific stylesheet. See #30532.

git-svn-id: https://develop.svn.wordpress.org/trunk@30866 602fd350-edb4-49c9-b593-d223f7449a82
Twenty Fifteen: remove license details for the image shown in the theme  screenshot file as it is Creative Commons Zero, which doesn't require attribution.

Props iamtakashi, fixes #30156.

git-svn-id: https://develop.svn.wordpress.org/trunk@30867 602fd350-edb4-49c9-b593-d223f7449a82
Twenty Twelve: fix widget stacking problem in older IE browsers for Front Page template.

Props TomasM, hiwhatsup. Fixes #28938.

git-svn-id: https://develop.svn.wordpress.org/trunk@30868 602fd350-edb4-49c9-b593-d223f7449a82
Twenty Fifteen: minor updates to readme.txt file for clarity and removing non-ASCII characters. Closes #30675.

git-svn-id: https://develop.svn.wordpress.org/trunk@30869 602fd350-edb4-49c9-b593-d223f7449a82
Customizer: Import missing `wp.customize.Control.prototype._toggleActive`.

Check also if `completeCallback` is set before calling it.

props westonruter.
see #30701.

git-svn-id: https://develop.svn.wordpress.org/trunk@30871 602fd350-edb4-49c9-b593-d223f7449a82
Customizer: Remove date filter from the Header/Background Image upload frames.

Adds an option to `wp.media.view.AttachmentsBrowser` to hide the date filter added in [29813].

see #30689.

git-svn-id: https://develop.svn.wordpress.org/trunk@30872 602fd350-edb4-49c9-b593-d223f7449a82
Add tests which ensure the `wp_editor_set_quality` and `jpeg_quality` filters only apply if they are added before the corresponding `WP_Image_Editor` is instantiated.

Props DH-Shredder
See #29856


git-svn-id: https://develop.svn.wordpress.org/trunk@30873 602fd350-edb4-49c9-b593-d223f7449a82
Clarify the behaviour of the `wp_editor_set_quality` and `jpeg_quality` filters.

Props DH-Shredder
See #29856


git-svn-id: https://develop.svn.wordpress.org/trunk@30874 602fd350-edb4-49c9-b593-d223f7449a82
Correct the height of the search type `select` element when searching the plugin directory.

See #30719
Props pavelevap, eliorivero


git-svn-id: https://develop.svn.wordpress.org/trunk@30879 602fd350-edb4-49c9-b593-d223f7449a82