Make settings available through context processor

Only partially implemented; not going to take this approach
Revert "Make settings available through context processor"

This reverts commit 88db1b53436ff214eb64f55004184a42aca75e0c.
Retrieve boilerplate text using template tag

New template tag will insert some pieces of commonly-reused text
Use boilerplate text

Pull some phrases from settings.py; only the simple templates for the
moment
Merge pull request #136 from knowledgecommonsdc/globals

Make sitewide content strings available as template tags