UI to load up the contents of URLs

[csarven]

UI to input a URL (or navigate to at a storage space using existing "resource browser"), fetch, then embed its contents into the dokieli document.

This may be a way to load up arbitrary data:

• If the content uses an RDF serialization except RDFa, it may need to be either embedded as a visible source block (e.g., like in a pre) or in a script block with accompanying mediatype.
• Similar to above if the content is non-RDF e.g., plain text, TeX, Markdown.

Possibly an option to transform the content into dokieli HTML+RDFa.

Perhaps some sugar-coating to load existing gists (crawl to raw file?)