wpView:
- Don't wrap single-line URLs in [embed]. Use them directly in generating a view.
- If the embedding HTML contains a script, "sandbox" it in an iframe to prevent it from changing the editor DOM.
- Automatically add toolbar and overlay when needed.
- Try to embed single-line URLs only if they are pasted in an empty paragraph.
Props avryl, see #28195
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git-svn-id: http://core.svn.wordpress.org/trunk@28562 1a063a9b-81f0-0310-95a4-ce76da25c4cd
Add a new 'Beta Testing' tab on the plugin installer, for features as plugins such as Press This.

fixes #28513.

Built from https://develop.svn.wordpress.org/trunk@28749


git-svn-id: http://core.svn.wordpress.org/trunk@28563 1a063a9b-81f0-0310-95a4-ce76da25c4cd
wpLink: use the proper instance of the editor when looking at the selection. Move the email and URL regexp to variables. See #19992
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git-svn-id: http://core.svn.wordpress.org/trunk@28564 1a063a9b-81f0-0310-95a4-ce76da25c4cd
wpLink: use simpler expressions to detect email address or URL. We are not validating user input here, just suggesting.

see #19992.
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git-svn-id: http://core.svn.wordpress.org/trunk@28565 1a063a9b-81f0-0310-95a4-ce76da25c4cd
Add "edit" mode for `[embed]` and URL media previews.

See #28532.

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git-svn-id: http://core.svn.wordpress.org/trunk@28566 1a063a9b-81f0-0310-95a4-ce76da25c4cd
Correct @return value for term_exists().

props simonwheatley.
fixes #28538.
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git-svn-id: http://core.svn.wordpress.org/trunk@28567 1a063a9b-81f0-0310-95a4-ce76da25c4cd
Merge branch 'master' into lazy_query_16910