Fix Link header parsing

[slorber]

Because of a parser bug in banana-rdf there's a bug here too.

The parsing of link headers have been temporarily disabled and must be rewired when the banana bug is fixed:
banana-rdf/banana-rdf#84

  def parseHeaders(base: Rdf#URI, headers: FluentCaseInsensitiveStringsMap): PointedGraph[Rdf] = {
    import collection.convert.wrapAsScala._
    // TODO we temporarily disable parsing of link headers because of a banana link header parsing bug:
    // https://github.com/w3c/banana-rdf/issues/84
    // val linkHeaders = Option(headers.get("Link")).map{_.toList}.getOrElse(Nil)
    val linkHeaders = Nil
    val linkgraph = union(linkHeaders.map(parser.parse(_).resolveAgainst(base)))
    PointedGraph(base, linkgraph)
  }

[slorber]

We need to remove my hack before closing this:

    // val linkHeaders = Option(headers.get("Link")).map{_.toList}.getOrElse(Nil)
    val linkHeaders = Nil