Borrowed janrain code from phylografter

Now supports login via FB, Google, etc.
First attempt at simple comments (using plugin_wiki comment tool)
Fix for anonymous (vs. logged-in) user
Moving comments to bottom of viewer
Crude working version of local-comemnts plugin (URL-based)
Basic working version of localcomments plugin
Improved style, improved deletion and claimed-expertise features
Merge branch 'local-comments'