anchor.diff:  * align caption to match alignment of block image
   * make conum glyphs configurable in theme (use reference table to resolve)
   * CJK and/or multilingual support (see https://github.com/chloerei/asciidoctor-pdf-cjk)
  - ** document this in the README
   * description list term should keep together with content (file issue)
   * allow font properties to be set for lists (description_list, outline_list)
   * remove pdfmarks file after optimizing
  
positive.code:  ** the problem here is that Prawn is allowing breaks at the boundaries of text fragments; it should only look at the contents
  * allow top as alternative to margin_top for all elements on title page (#431)
  * swallowing exceptions! (any use of e.message in a string is dangerous)
  * allow ordered list marker to be prefixed by section number (a global setting?)
  * conum not aligned vertically with callout text (perhaps too small?)
  * conum should never wrap (push it into the text if necessary)
  * decouple theme settings for section titles and discrete headings
  
negative.code: * FILE ISSUE: when split source listing, add top padding to bounding box (or is it the line metrics top?)
   ** perhaps this has to do with the a miscalculation in dry run when not starting from same y position?
   ** separate theme control for listing vs literal block (and maybe source too)
  * support URL images in running content (need to delegate to resolve_image_path)
  * add feature to number bullets according to section number (needed for OpenDevise agreements)
   ** allow ordered list marker to be prefixed by section number (a global setting?)
  * outline should link to title page if there's a cover page (skip cover page and ensuing blank page)
  * don't allow title page content to jump to next page
  * might be better to organize fragments of source chunks by lines (and pass that around) to simplify post-processing
  