Link references.
Introduce block references.
Use different image placeholder.
Make sure the image gets updated when the image file is created initially.
Moved back some basic node surfaces back to substance-nodes.
Blob vs. ArrayBuffer.
Blob
document -> window.document
node-webkit-ify.
Adjust schema of Contributor nodes.
Link -> Webpage
Update figure.js
Blobs for image display.
Just a comment.
Fix in TextSurface.
Refactorings.

- TestView, NodeView
- Component API.
Content API refactoring continued.
Add a dedicated 'document' node.
Fix.
Minor optimization in text view.

Don't react on empty deletes.