Further Abstract the OTT Site Structure

[dbudzins]

At the moment, we have a "hard-coded" initial landing page, which is a page with a list of shelves. However, that means there's no way to make a library page, series page, or even an in-line player page the default that users will see when they open the site. In theory we could abstract the landing page into an "other" media type and have the app config just specify the ID of the item for the landing page and for any other 'library' pages. Pages could also be embedded in playlists wherever makes sense.

Types of pages:

1. Shelf list (landing page)
2. Library
3. Series
4. Inline player
5. Search