Continue fleshing out experimental linking functionality.

Added a JSON endpoint to the docs controller to allow creating links
via a JS object that contains the source, destination, and access point
IDs, plus optional type and description info. This should be paired with
another endpoint in the Links controller for deleting links by ID.
Add spec for testing JSON endpoints
New documentaryApp
Merge branch 'master' of https://github.com/PonteIneptique/docview
into PonteIneptique-master

Conflicts:
	app/controllers/DocumentaryUnits.scala
	app/controllers/Links.scala
	app/views/common/relatedLinks.scala.html
	app/views/documentaryUnit/show.scala.html
	conf/routes
	public/javascripts/AnnotatePopup.js
	test/APISpec.scala