Neighboring embeds collapse together

[thomsbg]

Quill collapses adjacent Leaf objects with identical formats into a single Leaf. This is desirable for normal inline formats, but causes some trouble with embed formats. For example, running these commands on the quilljs.com homepage throws a javascript error:

quill.setContents({ ops: [] })
quill.insertEmbed(0, 'image', '/images/quill-photo.jpg')

// throws an error related to shifting the cursor,
// expected two <img> elements, but there is only one.
quill.insertEmbed(0, 'image', '/images/quill-photo.jpg')

console.log(JSON.stringify(quill.getContents())
// "{"ops":[{"attributes":{"image":"/images/quill-photo.jpg"},"insert":"!!\n"}]}"

I'm not sure of the best solution for this, but it seems like adjacent embeds shouldn't collapse in order to reflect the desired markup: <div><img><img></div>. Also, the newline probably shouldn't have the embed format either. i.e. the call to getContents() after these operations should look like:

{ ops: [
  { insert: 1, attributes: { image: '/images/quill-photo.jpg' } },
  { insert: 1, attributes: { image: '/images/quill-photo.jpg' } },
  { insert: '\n' }
] }