anchor.diff:  * add sample SVG to content of chronicles-example.adoc (we do already use one for title page)
   * 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?)?
  -* SIMPLE: missing text_transform in some places in theming guide
   * support zero-leading integers (use dedicated type like w/ roman numerals) in reversed order lists
   * 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?
  
positive.code: * make source code highlighting theme configurable (should be now, but has problems with conums); still?
  * use or don't use pad method? check performance
  
  == Documentation
  
  * control page numbering using pagenums attribute
  
negative.code: * allow background color to be set for heading
  * allow border to be set around block image
  * switch wolpertinger to howling wolf mouse
  * file issue in prawn to dispatch to image handler for images it doesn't know about
  * support arbitrary numeric entities (convert to unicode)
  * add brief mention in theming guide that deeper customizations can be achieved by extending the converter
  * allow alignment of list to be set separately from base align (and perhaps a hint in document)
  