Update Spark lexicon #6

According to this post, Spark updated their lexicon, and users can update their old posts to use the new lexicon.

There seems to be two major changes to posts that have been created/updated with the new lexicon:

• Posts that have created/updated with the new lexicon have the text field under a new caption field. This does not apply to replies which appear to be unchanged.
• The embed field is gone, replaced with media. The $type of embeds have similarly been changed, e.g. so.sprk.embed.video to so.sprk.media.video.

Strangely, in the examples I've seen, the $type of individual image elements in the array seem to be either absent or using the old so.sprk.embed.images#image.

(It was a bit difficult to compare due to the option to update old posts)