video.js will do its own fullscreen
Use "poster_url" instead of "url" for VideoInteractives
Use the 'show' partial in authoring mode
Add link to create VideoInteractive
Add VideoSource model [#48924359]

This lets a VideoInteractive have several formats to serve, i.e. mp4, ogg versions of the same video.

https://www.pivotaltracker.com/story/show/48924359
Fixing a bad flash message
Integrating VideoSources with VideoInteractives
rm inaccurate comments
Force the VideoInteractive to have a VideoSource

For some reason if we don't start with at least one VideoSource in place (even an empty one) the nested_form_for falls over. [#48924359]

https://www.pivotaltracker.com/story/show/48924359
Improving display of VideoInteractives