Add paragraph tags to 'Add Existing User' section on 'Add New User' screen in multisite.

props jkudish, topher1kenobe.
fixes #20271.
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git-svn-id: http://core.svn.wordpress.org/trunk@28460 1a063a9b-81f0-0310-95a4-ce76da25c4cd
Display the site scheme, not the current scheme on Edit Site screen in network admin.

props johnbillion.
fixes #28406.
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git-svn-id: http://core.svn.wordpress.org/trunk@28461 1a063a9b-81f0-0310-95a4-ce76da25c4cd
Avoid stomping of the $plugin variable in activate_plugin().

fixes #28102.
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git-svn-id: http://core.svn.wordpress.org/trunk@28462 1a063a9b-81f0-0310-95a4-ce76da25c4cd
Twenty Fourteen: change hardcoded pagination base to use the WordPress Rewrite object's `pagination_base` value instead. Document global variable usage properly.

Props SergeyBiryukov, fixes #28405.
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git-svn-id: http://core.svn.wordpress.org/trunk@28463 1a063a9b-81f0-0310-95a4-ce76da25c4cd
Plugin activation/deletion errors should be styled as such.

props johnbillion.
fixes #28260.
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git-svn-id: http://core.svn.wordpress.org/trunk@28464 1a063a9b-81f0-0310-95a4-ce76da25c4cd
Capitalize 'ID' correctly to avoid random failures of Tests_Tax_Query::test_term_taxonomy_id_field_no_taxonomy().

see #25284.
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git-svn-id: http://core.svn.wordpress.org/trunk@28465 1a063a9b-81f0-0310-95a4-ce76da25c4cd
Fix typo in mbstring_binary_safe_encoding() description.

props ghost1227.
fixes #28423.
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git-svn-id: http://core.svn.wordpress.org/trunk@28466 1a063a9b-81f0-0310-95a4-ce76da25c4cd
In `WPPlaylistView::ended()`, at the end of a playlist, set the index to `0` and call `->setCurrent()` instead of `->loadCurrent()` so that the first track is properly highlighted.

Fixes #28428.

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git-svn-id: http://core.svn.wordpress.org/trunk@28467 1a063a9b-81f0-0310-95a4-ce76da25c4cd
In the spirit of [27622], add a few CSS rules to ensure that videos will be responsive, regardless of theme.

Props Funkatronic.
Fixes #28414.

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git-svn-id: http://core.svn.wordpress.org/trunk@28468 1a063a9b-81f0-0310-95a4-ce76da25c4cd
Add oEmbed support for TED talks.

props pdclark.
fixes #28285.
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git-svn-id: http://core.svn.wordpress.org/trunk@28469 1a063a9b-81f0-0310-95a4-ce76da25c4cd
Because of YouTube's overwhelming dominance in the online video space, we should help our users who paste bad URLs when possible. It is easy to fix `http://youtube.com/embed/acb1233` URLs by turning them into `http://youtube.com/watch?v=abc1233` embeds using an embed handler (we already have one to fix Google Video embeds).

We should avoid doing this in almost every other case, but it's YouTube, and it's an easy error for a novice to make.

Fixes #24660.

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git-svn-id: http://core.svn.wordpress.org/trunk@28470 1a063a9b-81f0-0310-95a4-ce76da25c4cd
Make sure `$post` is properly documented as optional where applicable.

See #28388.

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Ensure `$post_id` is documented as optional where applicable.

See #28388.

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Be more specific that `$post_id` does not default to the ID of the global `$post` in some cases.

See [28654]. See #28388.

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git-svn-id: http://core.svn.wordpress.org/trunk@28473 1a063a9b-81f0-0310-95a4-ce76da25c4cd
Improve inline documentation for wp-includes/load.php.

Props ericlewis, DrewAPicture.
Fixes #24886.

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git-svn-id: http://core.svn.wordpress.org/trunk@28474 1a063a9b-81f0-0310-95a4-ce76da25c4cd
Mark the `MYSQL_NEW_LINK` constant as deprecated in 3.9+ as no equivalent to the `$new_link` parameter exists in `mysqli_*` functions.

Fixes #27933.

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Make sure to use 3-digit x.x.x style for two 3.9.0 `@since` versions.

Props netweb.
Fixes #28446.

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git-svn-id: http://core.svn.wordpress.org/trunk@28476 1a063a9b-81f0-0310-95a4-ce76da25c4cd
Fix SQL generation when `meta_query` has an `'relation' => 'OR'` for its queries and wants to `'orderby' => 'meta_value'`.

Adds unit test.

Props jackreichert.
Fixes #25538.


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git-svn-id: http://core.svn.wordpress.org/trunk@28477 1a063a9b-81f0-0310-95a4-ce76da25c4cd
Improve inline documentation for the `__construct()` and `add()` methods in `WP_Error` class.

Props jdgrimes.
Fixes #28203.

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git-svn-id: http://core.svn.wordpress.org/trunk@28478 1a063a9b-81f0-0310-95a4-ce76da25c4cd
Twenty Fourteen: add documentation for global variables used in `twentyfourteen_wp_title()`. Closes #28421.
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