anchor.diff:  * flesh out title page more
     - document subtitle (partially solved)
   * don't create title page for article doctype
  -* chapter name in footer
  +* chapter name in footer (need a proper hook for writing to the footer; perhaps also template in theme for footer text)
   * implement toc and activate if toc is set on document (need to reorder pages)
   * inline image
   * callbacks for title page, new part, new chapter, etc
  
positive.code: * move check for node.title? inside layout_caption
  * theme idea / tester: see sandbox/ebook-learn_version_control_with_git-SAMPLE.pdf
  * make alternating page title position optional (via theme?)
  * page numbers are off in Clojure Cookbook
  
  * enable pagenums attribute by default (may require changes to how we handle attributes)
  * start page numbering on first page if no title page
  
negative.code: 
  == TODO
  
  * prawn-svg should drop layer with display: none style
  * add note to README that Prawn will subset any fonts provided
  * nested keep_together logic is broken (e.g., example inside example, listing inside sidebar, etc)
  * look into single_line + shrink_to_fit in listings, perhaps other places
  * refactor as Prawn view to avoid method name conflicts (also see https://github.com/prawnpdf/prawn/issues/802)
  * SVG image is getting cut off when at boundary of page
  * create proper default (Asciidoctor) theme
  * start number for conum in theme
  