So I'm wondering looking at the media stuff in the CreatePostView.. would it be more sensible to spin this out to its own view? (rendered as a child of createpost or something).

Feels like it might be tidier:
* this.media goes to this.model
* HTML for dropzone moves to its own template
* the whole thing can be reused more easily
* forward the success/failure events to events on the view. Anything else can subscribe to these as needed (to get the media id after upload etc)
* could have multiple instances if we're have multiple upload fields (maybe?)