Enable Media Embedding in posts (via s9e TextFormatter)

Now that we use s9e Text Formatter, I think it would be good to enable the use of its Media Embed plugin:
http://s9etextformatter.readthedocs.io/Plugins/MediaEmbed/Synopsis/

At this point I think it's safe to say the ability to post embedded video or adio content is no longer something we can consider "bloat". It would, IMO, be a step forward towards modernity if we could make this a native feature, rather than expecting extensions to continue handling it.