Start using neighbors (WIP) and summary plugins, req's pelican-git.

'summary' plugin uses features not yet available (sigh) in a release
version of pelican, so just using pelican-git for the time being.

(See https://github.com/getpelican/pelican-plugins/issues/54.)
Integrate 'summary' into bootstraped template.
Fix facebook link.  Thanks, Clare! :D
Add 'new blog' initial post.
Tweak index.html: no pages list, no welcome text.