added "text" and "spec" rows
add todo re docs sharing
added related content fetching from Source & added Renderer documentation
added extension mapping & meta information loading
added related content fetching
added related content fetching
updated to new stream-oriented API
updated to new stream-oriented API
updated to new stream-oriented API
added unit tests for meta-information fetching
added unit tests for meta-information fetching
updated documentation for new stream-oriented API and meta-information loading
implemented format listing for "file" source