Remove remaining Heartbeat API experimental notices

Props DH-Shredder.
Fixes #28626.

Built from https://develop.svn.wordpress.org/trunk@28872


git-svn-id: http://core.svn.wordpress.org/trunk@28672 1a063a9b-81f0-0310-95a4-ce76da25c4cd
Perform a canonical redirect for posts that are published but are visited at a `?p=123&preview=true` URL.

Props amit, joostdevalk.
Fixes #20496.

Built from https://develop.svn.wordpress.org/trunk@28874


git-svn-id: http://core.svn.wordpress.org/trunk@28673 1a063a9b-81f0-0310-95a4-ce76da25c4cd
Remove obsolete `wp_cache_delete('get_pages', 'posts')` from `clean_post_cache()`.

Fixes #27459.

Built from https://develop.svn.wordpress.org/trunk@28875


git-svn-id: http://core.svn.wordpress.org/trunk@28674 1a063a9b-81f0-0310-95a4-ce76da25c4cd
Make the posts list table mode a sticky user setting. props garyc40, azaozz, ericmann. fixes #16774, #20335.

Built from https://develop.svn.wordpress.org/trunk@28876


git-svn-id: http://core.svn.wordpress.org/trunk@28675 1a063a9b-81f0-0310-95a4-ce76da25c4cd
Fix the spacing between the wp-pointer arrow and bubble in LTR and RTL.

Fixes #28062.


Built from https://develop.svn.wordpress.org/trunk@28877


git-svn-id: http://core.svn.wordpress.org/trunk@28676 1a063a9b-81f0-0310-95a4-ce76da25c4cd
Fix typo in a comment.

props JustinSainton.
see #20496.
Built from https://develop.svn.wordpress.org/trunk@28878


git-svn-id: http://core.svn.wordpress.org/trunk@28677 1a063a9b-81f0-0310-95a4-ce76da25c4cd
Add `->get_quality()` method to `WP_Image_Editor` class.

Adds unit tests.

Props markoheijnen.
Fixes #28154.

Built from https://develop.svn.wordpress.org/trunk@28879


git-svn-id: http://core.svn.wordpress.org/trunk@28678 1a063a9b-81f0-0310-95a4-ce76da25c4cd
If the `get_the_excerpt()` is called out of bounds of a global `$post`, return ''.

Fixes #22413.

Built from https://develop.svn.wordpress.org/trunk@28880


git-svn-id: http://core.svn.wordpress.org/trunk@28679 1a063a9b-81f0-0310-95a4-ce76da25c4cd
In multisite, on the `updated_option` action, if the option name is one of: 'blogname', 'siteurl', 'post_count' - refresh the blog details cache for the current blog id.

Adds unit test.

Props kovshenin.
Fixes #26410.

Built from https://develop.svn.wordpress.org/trunk@28881


git-svn-id: http://core.svn.wordpress.org/trunk@28680 1a063a9b-81f0-0310-95a4-ce76da25c4cd
`wp_extract_urls()` should not match dates.

Updates unit tests.

Props hinnerk, sergej.mueller.
Fixes #28222.

Built from https://develop.svn.wordpress.org/trunk@28882


git-svn-id: http://core.svn.wordpress.org/trunk@28681 1a063a9b-81f0-0310-95a4-ce76da25c4cd
`remove_all_filters()` should set to `array()`, not call `unset()`.

Props nacin, c3mdigital.
Fixes #19306.

Built from https://develop.svn.wordpress.org/trunk@28883


git-svn-id: http://core.svn.wordpress.org/trunk@28682 1a063a9b-81f0-0310-95a4-ce76da25c4cd
After [28883], `remove_filter()` should set `$GLOBALS['wp_filter'][ $tag ]` to `array()` when empty.

Props wonderboymusic, sphoid.
Fixes #28142.

Built from https://develop.svn.wordpress.org/trunk@28884


git-svn-id: http://core.svn.wordpress.org/trunk@28683 1a063a9b-81f0-0310-95a4-ce76da25c4cd
Add new action 'delete_user_form' in `wp-admin/users.php` and `wp-admin/network/users.php`.

Props SergeyBiryukov, usermrpapa.
Fixes #27230.

Built from https://develop.svn.wordpress.org/trunk@28885


git-svn-id: http://core.svn.wordpress.org/trunk@28684 1a063a9b-81f0-0310-95a4-ce76da25c4cd
Update `@param` docs in `plugin.php`

Props dkotter.
Fixes #28516.

Built from https://develop.svn.wordpress.org/trunk@28886


git-svn-id: http://core.svn.wordpress.org/trunk@28685 1a063a9b-81f0-0310-95a4-ce76da25c4cd