Customizer: Make panel title translatable too.

props michalzuber.
see #27406.
Built from https://develop.svn.wordpress.org/trunk@29135


git-svn-id: http://core.svn.wordpress.org/trunk@28919 1a063a9b-81f0-0310-95a4-ce76da25c4cd
Media Grid improvements:

* Remove fixed elements.
* Adjusts toolbar and search, fixes #28833.
* Add link to Add New button, fixes #28825.
* Add "Edit Metadata" tab to all items, "Edit Image" only for images
* Make strings translatable.
* First pass for help tab.

see #28850.
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git-svn-id: http://core.svn.wordpress.org/trunk@28920 1a063a9b-81f0-0310-95a4-ce76da25c4cd
Fix mismatches in access modifiers for `WP_List_Table` + subclasses.

Fixes #28843, #28879.

Built from https://develop.svn.wordpress.org/trunk@29137


git-svn-id: http://core.svn.wordpress.org/trunk@28921 1a063a9b-81f0-0310-95a4-ce76da25c4cd
4.0-beta1-29138.

Built from https://develop.svn.wordpress.org/trunk@29138


git-svn-id: http://core.svn.wordpress.org/trunk@28922 1a063a9b-81f0-0310-95a4-ce76da25c4cd
Fill out inline documentation for magic methods added to the `WP_Text_Diff_Renderer_Table` class in [28525].

See #27881, #22234 and #28885.

Built from https://develop.svn.wordpress.org/trunk@29139


git-svn-id: http://core.svn.wordpress.org/trunk@28923 1a063a9b-81f0-0310-95a4-ce76da25c4cd
Fill out inline documentation for magic methods added to the `WP_User_Query` class in [28528].

See #27881, #22234 and #28885.

Built from https://develop.svn.wordpress.org/trunk@29140


git-svn-id: http://core.svn.wordpress.org/trunk@28924 1a063a9b-81f0-0310-95a4-ce76da25c4cd
Fill out inline documentation for magic methods added to the `WP_Query` class in [28523].

See #27881, #22234 and #28885.

Built from https://develop.svn.wordpress.org/trunk@29141


git-svn-id: http://core.svn.wordpress.org/trunk@28925 1a063a9b-81f0-0310-95a4-ce76da25c4cd
Fill out inline documentation for magic methods added to the `WP_MatchesMapRegex` class in [28516].

See #27881, #22234 and #28885.

Built from https://develop.svn.wordpress.org/trunk@29142


git-svn-id: http://core.svn.wordpress.org/trunk@28926 1a063a9b-81f0-0310-95a4-ce76da25c4cd
Fill out inline documentation for magic methods added to the `Walker` class in [28514].

See #27881, #22234 and #28885.

Built from https://develop.svn.wordpress.org/trunk@29143


git-svn-id: http://core.svn.wordpress.org/trunk@28927 1a063a9b-81f0-0310-95a4-ce76da25c4cd
Fill out inline documentation for magic methods added to the `WP_Error` class in [28511].

See #27881, #22234 and #28885.

Built from https://develop.svn.wordpress.org/trunk@29144


git-svn-id: http://core.svn.wordpress.org/trunk@28928 1a063a9b-81f0-0310-95a4-ce76da25c4cd
Fill out inline documentation for magic methods added to the `WP_Ajax_Response` class in [28524].

See #27881, #22234 and #28885.

Built from https://develop.svn.wordpress.org/trunk@29145


git-svn-id: http://core.svn.wordpress.org/trunk@28929 1a063a9b-81f0-0310-95a4-ce76da25c4cd
Fill out inline documentation for magic methods added to the `WP_Object_Cache` class in [28502], [28521], [28524].

See #27881, #22234 and #28885.

Built from https://develop.svn.wordpress.org/trunk@29146


git-svn-id: http://core.svn.wordpress.org/trunk@28930 1a063a9b-81f0-0310-95a4-ce76da25c4cd
Fill out inline documentation for magic methods added to the `WP_Filesystem_Base` class in [28521].

See #22234 and #28885.

Built from https://develop.svn.wordpress.org/trunk@29147


git-svn-id: http://core.svn.wordpress.org/trunk@28931 1a063a9b-81f0-0310-95a4-ce76da25c4cd
Fill out inline documentation for magic methods added to the `WP_List_Table` class in [28493], [28521], and [28524].

See #22234 and #28885.

Built from https://develop.svn.wordpress.org/trunk@29148


git-svn-id: http://core.svn.wordpress.org/trunk@28932 1a063a9b-81f0-0310-95a4-ce76da25c4cd
Fill out inline documentation for magic methods added to the `Custom_Background` class in [28481], [28521], and [28524].

See #22234 and #28885.

Built from https://develop.svn.wordpress.org/trunk@29149


git-svn-id: http://core.svn.wordpress.org/trunk@28933 1a063a9b-81f0-0310-95a4-ce76da25c4cd
Fill out inline documentation for magic methods added to the `Custom_Image_Header` class in [28481], [28521], and [28524].

See #22234 and #28885.

Built from https://develop.svn.wordpress.org/trunk@29150


git-svn-id: http://core.svn.wordpress.org/trunk@28934 1a063a9b-81f0-0310-95a4-ce76da25c4cd
Inline documentation cleanup for 4.0 audit.

* Alignment for the 'term_search_min_chars' hook docs, added in [28892]
* Globals added for `wp_ajax_parse_embed()`, added [28580]

See #28885.

Built from https://develop.svn.wordpress.org/trunk@29151


git-svn-id: http://core.svn.wordpress.org/trunk@28935 1a063a9b-81f0-0310-95a4-ce76da25c4cd
Inline documentation for the 'plugin_install_details_link' hook added in [29047] should use a 3-digit, x.x.x-style `@since` version.

See #28885.

Built from https://develop.svn.wordpress.org/trunk@29152


git-svn-id: http://core.svn.wordpress.org/trunk@28936 1a063a9b-81f0-0310-95a4-ce76da25c4cd
Fill out inline documentation for the `__call()` magic method added to the `WP_Roles` class in [28503].

See #22234 and #28885.

Built from https://develop.svn.wordpress.org/trunk@29153


git-svn-id: http://core.svn.wordpress.org/trunk@28937 1a063a9b-81f0-0310-95a4-ce76da25c4cd
Inline documentation cleanup for 4.0 audit.

* phpDoc tweaks for `wp_get_available_translations_from_api()`, `wp_install_download_language_pack()`, and `wp_install_load_language()`, added in [29018]
 
See #28885.

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