Audio/Video shortcodes in the media modal:

* Add `embedMimes` to `_wpMediaViewsL10n`
* Use `escape` instead of `interpolate` when setting attributes in Underscore templates
* When creating the `<audio>` and `<video>` tags dynamically, set inner `<source>` nodes instead of the `src` attribute and properly set the mime-type per source as the `type` attribute. This is also drastically reduces the amount of code used to generate the tags.

See #27016.


Built from https://develop.svn.wordpress.org/trunk@27476


git-svn-id: http://core.svn.wordpress.org/trunk@27320 1a063a9b-81f0-0310-95a4-ce76da25c4cd
In `wp.media.model.PostAudio` and `wp.media.model.PostVideo`, use Underscore's `unset` method when clearing out properties when the attachment changes.

See #27016.


Built from https://develop.svn.wordpress.org/trunk@27477


git-svn-id: http://core.svn.wordpress.org/trunk@27321 1a063a9b-81f0-0310-95a4-ce76da25c4cd
Audio/Video shortcodes in the media modal:

* Make a generic model, `wp.media.model.PostMedia`, which replaces `wp.media.model.PostAudio` and `wp.media.model.PostVideo`
* Make a generic library, `wp.media.controller.MediaLibrary`, which replaces `wp.media.controller.ReplaceVideo` and `wp.media.controller.ReplaceAudio`
* `wp.media.controller.MediaLibrary` is used to create new states that want to load a library filtered by type, making it incredibly simple to add states to frames. See `wp.media.view.MediaFrame.VideoDetails` and `wp.media.view.MediaFrame.AudioDetails`.

UX changes:

* Add the ability to manage HTML5 fallbacks - add additional `<source>`s or remove specific `<source>`s
* In the Video Details state, add the ability to select a poster image

See #27016.


Built from https://develop.svn.wordpress.org/trunk@27478


git-svn-id: http://core.svn.wordpress.org/trunk@27322 1a063a9b-81f0-0310-95a4-ce76da25c4cd
Add `wp.media.view.MediaFrame.MediaDetails`, which `wp.media.view.MediaFrame.AudioDetails` and `media.view.MediaFrame.VideoDetails` extend. The subclasses subsequently only need to set `createStates()` and `bindHandlers()`, as well as any missing toolbar views.

See #27016.


Built from https://develop.svn.wordpress.org/trunk@27479


git-svn-id: http://core.svn.wordpress.org/trunk@27323 1a063a9b-81f0-0310-95a4-ce76da25c4cd
Since audio and video shortcodes don't point at actual attachments, don't persist the library's selection. Move the media instructions in the block that scrolls.

See #27016.


Built from https://develop.svn.wordpress.org/trunk@27480


git-svn-id: http://core.svn.wordpress.org/trunk@27324 1a063a9b-81f0-0310-95a4-ce76da25c4cd