anchor.diff:  
   == TODO
   
  -* remove text justification hack (#92) (PR sent)
  -* warn in case when target of inter-document xref can't be resolved, but xref has explicit text
   * don't add image from front matter if already referenced by chapter
  -* add document filename to warn messages
  +* add document filename to warn messages (added for some)
   * look for front-matter.html relative to docdir (or base_dir?); also allow front-matter.xhtml
   * change references[:spine] to spine_document property
  +* make sure every doc is assigned an ID (perhaps it already is) so we don't need to rely on the docname attr as a fallback
  + ** I believe this is already true; just remove hack
   * add helper to resolve imagesdir
   * support inline SVG
  -* describe the leveloffset setting in more detail
  +* describe the leveloffset setting in more detail in the README
   * link to https://medium.com/@sandersk/responsive-ebook-design-a-primer-8bba01328219 in style section in README
   * why don't we just use the chapter filename as the id?
   * only uppercase document title if detected in CSS
   * add empty front matter page in kf8 version if one is specified to allow navigation to first entry from TOC
    ** why can't we navigate to first chapter on Kindle from TOC?
  -* allow imagesdir to be customized (#22)
  +* allow imagesdir to be outside of docdir (#22)
   * document more clearly how to provide your own CSS
    ** currently it's not possible to override the epub3-fonts.css (though it should be)
   * add nav entry for cover if format != :kf8 ?
   * cleanup this sanitize XML stuff; move to Asciidoctor::Helpers?
    ** also need an upcase_pcdata
   * allow role to be applied to chapter (which means the role must be on the document)
  -* make sure every doc is assigned an ID (perhaps it already is) so we don't need to rely on the docname attr as a fallback
  - ** I believe this is already true; just remove hack
   * should we enable hyphens in non-Kindle?
    ** we can reenable once we confirm it doesn't crash Kindle for Mac
   * switch to epubcheck-ruby
    ** epubcheck-ruby 4.0.2
    ** supports options such as -q
    ** add -w option by default (perhaps allow additional options to be passed via the ebook-validate attribute)
  -* store spine as map in references?
  +* document KINDLEGEN and EPUBCHECK env vars
   * part vs chapter? a difference?
   
   * create a video to demonstrate Google Play Books read aloud reading complete sentences in books generated with Asciidoctor EPUB3
  
positive.code: 
  == NOTES
  
  * content must be XHTML (not HTML)
  * Aldiko uses the image on the cover page (or a screenshot of the cover page) as the image in the bookshelf
  * use -webkit-transform: translate/translateX/translateY to move objects from origin by relative distances (alternative to relative positioning, which is not permitted on Kindle)
  * don't need attributes above header in sub-documents anymore (except for PDF; we'll cross that bridge when we get to it)
  
negative.code: 
  //^
  .Converter
  * CRITICAL: put e-book reader class on html instead of body
  * CRITICAL: surround prose in <span> (e.g., simple <dd>) which is not nested in <p> or <div> so iBooks can change the font
  * CRITICAL: don't drop subsequent paragraphs of preamble when abstract is found...need to pass them through
  * CRITICAL: if document doesn't have doctitle, Untitled shows in epub2 TOC (isn't this correct?)
  * CRITICAL: try to pull username from author email field; pull avatar from gravatar
  * CRITICAL: make generated file name strategy configurable (source file vs id)
  * HIGH: revisit the headshot image logic
  * HIGH: if running on a single article, then the document id has a conflicting purpose
  * HIGH: require spine option on include directive in order to create a chapter file (requires change in Asciidoctor)
  * HIGH: promote regexps to constants
  * HIGH: use more thorough image path resolution
  * HIGH: put shy marks after dashes to allow wrapping to occur in text justification
  * MEDIUM: add landmarks nav list to nav.xhtml; see https://github.com/IDPF/epub3-samples/blob/master/31/moby-dick-mo-xhtml/EPUB/toc.xhtml
  * MEDIUM: Kindle links to cover page when clicking on first chapter instead of first chapter page
  * MEDIUM: add icon & icon placement as attributes on btn macro
  * MEDIUM: move client sniffer JavaScript to file and read/include from converter
  * MEDIUM: use the dfn element for defining a definition of a term (not just term class); see https://developer.mozilla.org/en-US/docs/Web/HTML/Element/dfn
  * MEDIUM: source highlighting using Rouge (instead of Pygments)
  * MEDIUM: to remove text indent in mobi7, set width="0pt" (text-indent) on <p> tag; also set height="1em" (margin top)
  * MEDIUM: create back link in bibliography entry for each reference to it (currently only the first)
  * packager doesn't resolve include files in subdirectory totally correctly
  * implement checklists
  * quiet flag
  * document that to use kindlegen with Ruby 1.9.3, must use kindlegen 2.9.4 gem (or specify KINDLEGEN env var)
  
  //^
  .Packager
  