Merge pull request #3 from 18F/guest-users

Add guest user capability
Push "Edit this link" into the edit_link include
Merge pull request #4 from 18F/editable-pages

Editable pages
Replace plugin-generated projects/ with Markdown
Replace plugin-generated wg/ with Markdown
Replace plugin-generated departments/ w/ Markdown
Replace plugin-generated locations/ with Markdown
Replace plugin-generated snippets/ with Markdown