anchor.diff:    - perhaps progit2 as well; others?
   
   == TODO
  +
  +* document show-link-uri in table on asciidoctor.org
   
   * recto/verso margins
     - account differences in top/bottom margins on recto/verso pages in running header/footer
  
positive.code: * allow alignment of list to be set separately from base align (and perhaps a hint in document)
  * due to order of loading, getting warnings when redefining methods in Asciidoctor core
  * prawn-pdfimage https://github.com/packetmonkey/prawn-pdfimage
  * rename ThemeLoader to ThemeReader?
  * document autofit option on verbatim blocks
  * document how to extend the converter, use Prawn
  * using tabs instead of spaces for source code indentation allows leading whitespace to be preserved when copying
  
  * *margin per heading level* (see https://github.com/asciidoctor/asciidoctor-pdf/issues/176)
  * document how to override the Ruby code to get custom styling in the theming guide
  
negative.code:   - get import_page to stop adding an extra page
    - blank page after title page if media=print
  
  * examine uses of attr/attr? and ensure we only inherit when desired
  * log warning with reason when remote image can't be read
  * inline images: allow built-in font family names for SVG to be remapped
  * inline images: should we be passing absolute image path in tag or something relative (or even a lookup id?)?
  * document missing keys in theming guide for 1.5.0.beta.1
    - missing text_transform in some places
  * support the reversed option on ordered lists (see https://github.com/asciidoctor/asciidoctor/issues/1830)
  * large image runs into running footer (doesn't bottom margin need to be aligned with running footer height?)
  * should str_to_pt helper handle % and vw units?
  * enable/implement key table_font_style
  * allow style of visible link to be controlled by theme
  * check that color of table edges set to table_grid_color??
  * shouldn't the default align for headings be $base_align??
  * should not wrap at formatting mark unless it is at a break opportunity
  * rename :entity to :charref in text parser
  * create value type for font style and font alignment for theming guide
  * force encoding of theme to UTF-8 (particularly for keys related to content)
  * be more consistent with how examples are shown in theming-guide.adoc (do we show last segment only?)
  