Add edit mode for MCE [embed] previews

[wonderboymusic]

Wouldn't it be killer if you could edit your embeds like you edit other media previews?

Patch incoming.

[wonderboymusic]

.2.diff​ accounts for the churn from avyrl's patch - both [embed] and URLs are supported for edit.

[wonderboymusic]

In 28752:

Add "edit" mode for [embed] and URL media previews.

See #28532.

[wonderboymusic]

I created a mixin so that embed and embedURL can share code. I highly suggest trying this feature out, it's pretty slick (pats self on back). Here are some URLs to test with:

​http://www.youtube.com/watch?v=ssqvhobab_Q
​https://soundcloud.com/disclosuremusic/frontin-pharrell-ft-jay-z-disclosure-re-work

[DrewAPicture]

Pretty cool. Probably the only thing left is to embed on paste a la #28195.

[azaozz]

Getting Cannot read property 'edit' of undefined when trying to edit a "plain URL" embed, pointing here: https://core.trac.wordpress.org/browser/trunk/src/wp-includes/js/mce-view.js#L43

[wonderboymusic]

type and shortcode mean different things, depending on whether it is a view or view.View. Some things need to refer to type - done in 28532.3.diff​

[wonderboymusic]

In 28775:

Diambiguate type and shortcode in TinyMCE view classes and their attached view.View class. Has the added feature of not causing JS errors.

See #28532.

[wonderboymusic]

In 28816:

wp.mce.embedView.fetch() and wp.media.view.EmbedLink.fetch() need to pass the same parameters.

Fixes #28532.