added document plugin and test
added document plugin to the test runner
absolute not relative urls ; include current location as link
added dublincore scraping ; also title is now extracted from scholar, dublincore if possible
added opengraph extraction
improved opengraph extraction/test
added uris method to return unique urls for the document
ensure annotations are unique when loading
list comprehension needs parens
synidcation links cant be used for identification of the document, since they are shared across so many resources
updated test to check for deduping of annotations when loading more
removed deduping behaviour from Store plugin
added favicon extraction based on needs at https://github.com/hypothesis/h/issues/431
need to dedupe and update existing annotations when adding more annotations by querying for related uris
Merge pull request #209 from edsu/dedupe-annotations

need to dedupe and update existing annotations when adding more annotati...
dublin core prefix in metadata should be case insensitive, since Eprints repository (and others) use uppercase form e.g. http://eprints.soton.ac.uk/273248/
look for rel="bookmark" too refs #86
Merge pull request #208 from edsu/okfn

document annotator plugin
Updated JS and CSS references in demo.html to match the new build system.
Use Node type constants

Thanks @csillag