Twenty Fifteen: Update the .pot file for [30834].

fixes #30152.
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git-svn-id: http://core.svn.wordpress.org/trunk@30835 1a063a9b-81f0-0310-95a4-ce76da25c4cd
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.
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git-svn-id: http://core.svn.wordpress.org/trunk@30836 1a063a9b-81f0-0310-95a4-ce76da25c4cd
Customizer: Don't escape control descriptions in JavaScript templates.

fixes #30682 for trunk.
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git-svn-id: http://core.svn.wordpress.org/trunk@30837 1a063a9b-81f0-0310-95a4-ce76da25c4cd
Customizer: Re-add the possibility to remove and restore a default background image.

see #21483.
fixes #30683 for trunk.
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git-svn-id: http://core.svn.wordpress.org/trunk@30839 1a063a9b-81f0-0310-95a4-ce76da25c4cd
Improve the fix for menu shakiness when over-scrolling. Recalculate heights on editor auto-resize.
See #30692.
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git-svn-id: http://core.svn.wordpress.org/trunk@30842 1a063a9b-81f0-0310-95a4-ce76da25c4cd
Editor, new DFW: fix fading out for the right sidebar in IE. Fixes #30714.
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git-svn-id: http://core.svn.wordpress.org/trunk@30843 1a063a9b-81f0-0310-95a4-ce76da25c4cd
Avoid repeatedly calling is_tax( 'post_format', '...' ) in get_the_archive_title().

see #21995.

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git-svn-id: http://core.svn.wordpress.org/trunk@30844 1a063a9b-81f0-0310-95a4-ce76da25c4cd
No need for wp_get_password_hint() to be prefixed as if it is private.

see #21243.

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git-svn-id: http://core.svn.wordpress.org/trunk@30845 1a063a9b-81f0-0310-95a4-ce76da25c4cd
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.

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git-svn-id: http://core.svn.wordpress.org/trunk@30846 1a063a9b-81f0-0310-95a4-ce76da25c4cd
About page design for 4.1.

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

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git-svn-id: http://core.svn.wordpress.org/trunk@30847 1a063a9b-81f0-0310-95a4-ce76da25c4cd