Support `loop` for `[audio]` and `[video]` shortcodes that specify files that are played using MediaElement's Flash plugin bridge.

Fixes #27368.


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git-svn-id: http://core.svn.wordpress.org/trunk@28191 1a063a9b-81f0-0310-95a4-ce76da25c4cd
When pausing "all" players attached to MCE views, don't reach into global scope and pause "every" player. Only pause the players bound to MCE views.

Fixes #27971.


Built from https://develop.svn.wordpress.org/trunk@28364


git-svn-id: http://core.svn.wordpress.org/trunk@28192 1a063a9b-81f0-0310-95a4-ce76da25c4cd
Update the default (WP-defined) styles for MediaElement players to be more in-line with our flat aesthetic. Use the new official colors. 

Props celloexpressions.
Fixes #27516.


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git-svn-id: http://core.svn.wordpress.org/trunk@28193 1a063a9b-81f0-0310-95a4-ce76da25c4cd
Avoid a notice in `wp_save_image()` by checking `$meta['sizes']['thumbnail']` for `! empty()` before setting a variable to it.

Props MikeHansenMe.
Fixes #17736.


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git-svn-id: http://core.svn.wordpress.org/trunk@28194 1a063a9b-81f0-0310-95a4-ce76da25c4cd
In `wp_read_image_metadata()`, the values from `exif_read_data()` should only override values from `iptcparse()` that are empty. 

Props SergeyBiryukov.
Fixes #23706.

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git-svn-id: http://core.svn.wordpress.org/trunk@28195 1a063a9b-81f0-0310-95a4-ce76da25c4cd
In `media_upload_gallery_form()`'s inline JavaScript, remove unnecessary comment tags.

Fixes #25637.


Built from https://develop.svn.wordpress.org/trunk@28368


git-svn-id: http://core.svn.wordpress.org/trunk@28196 1a063a9b-81f0-0310-95a4-ce76da25c4cd
In the `Attachment Details` section of the media modal, only add `box-shadow` to images. Other mime-type icons look strange with an arbitrary border.

Props avryl.
Fixes #27949.


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git-svn-id: http://core.svn.wordpress.org/trunk@28197 1a063a9b-81f0-0310-95a4-ce76da25c4cd
Allow users to set overrides for MediaElement instances by always passing `_wpmejsSettings` instead of just `_wpmejsSettings.pluginPath`.

Props Otto42 for the initial patch.
Fixes #25243.


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git-svn-id: http://core.svn.wordpress.org/trunk@28198 1a063a9b-81f0-0310-95a4-ce76da25c4cd