2331 breadcrumb delimiter addition

This is a second PR that contains only the relevant files. See the original PR for discussion [https://github.com/apache/couchdb-fauxton/pull/66]. Sorry for the fuss. Git can be bloody confusing.
This has too much logic for a template. What would be better here is to define a function in the `serialize` method that you could call here, something like:

    if (isNextTextLabel(index, crumb)) { 
      /* add divider */ 
    }