Properly invalidate the cache for `wp_count_posts()` on insert, trash, or when transitioning `post_status` inside of `_transition_post_status()`. Introduces `_count_posts_cache_key()`. Adds unit tests.

Props mark8barnes, for bringing this to our attention in an initial patch.
Fixes #21879.


Built from https://develop.svn.wordpress.org/trunk@27081


git-svn-id: http://core.svn.wordpress.org/trunk@26954 1a063a9b-81f0-0310-95a4-ce76da25c4cd
Add braces around conditionals. props TobiasBg. fixes #25704.
Built from https://develop.svn.wordpress.org/trunk@27082


git-svn-id: http://core.svn.wordpress.org/trunk@26955 1a063a9b-81f0-0310-95a4-ce76da25c4cd
TinyMCE: don't replace <i> with <em> and <b> with <strong> and don't remove them when empty, see #24067, see #23037.
Built from https://develop.svn.wordpress.org/trunk@27083


git-svn-id: http://core.svn.wordpress.org/trunk@26956 1a063a9b-81f0-0310-95a4-ce76da25c4cd
Add back missing var definition in wplink.js, props TobiasBg, see #24067
Built from https://develop.svn.wordpress.org/trunk@27084


git-svn-id: http://core.svn.wordpress.org/trunk@26957 1a063a9b-81f0-0310-95a4-ce76da25c4cd
Minor cleanup (jshint) of wp-fullscreen.js and /wordpress/plugin.js, see #24067
Built from https://develop.svn.wordpress.org/trunk@27085


git-svn-id: http://core.svn.wordpress.org/trunk@26958 1a063a9b-81f0-0310-95a4-ce76da25c4cd
Invalidate the post cache for posts associated with a user who has been removed from a blog in `remove_user_from_blog()`. Adds a unit test.

Props nprasath002 for the initial patch.
Fixes #25545.


Built from https://develop.svn.wordpress.org/trunk@27087


git-svn-id: http://core.svn.wordpress.org/trunk@26959 1a063a9b-81f0-0310-95a4-ce76da25c4cd
Inline documentation for hooks in wp-admin/network/sites.php.

Props NikV, kpdesign.
Fixes #26124.

Built from https://develop.svn.wordpress.org/trunk@27088


git-svn-id: http://core.svn.wordpress.org/trunk@26960 1a063a9b-81f0-0310-95a4-ce76da25c4cd
Inline documentation for hooks in wp-admin/includes/class-wp-terms-list-table.php.

Props Ajay, kpdesign.
Fixes #26209.

Built from https://develop.svn.wordpress.org/trunk@27089


git-svn-id: http://core.svn.wordpress.org/trunk@26961 1a063a9b-81f0-0310-95a4-ce76da25c4cd
Inline documentation for hooks in wp-admin/includes/class-wp-ms-themes-list-table.php.

Also marks two hooks in wp-admin/includes/class-wp-themes-list-table.php as duplicates.

Props ShinichiN, kpdesign, DrewAPicture.
Fixes #25608.

Built from https://develop.svn.wordpress.org/trunk@27090


git-svn-id: http://core.svn.wordpress.org/trunk@26962 1a063a9b-81f0-0310-95a4-ce76da25c4cd