anchor.diff:   ** Let giblish generate a clickable graph of all document references (requires
       graphviz and the 'dot' tool).
   
  -NOTE: giblish shall be considered stable from a usage perspective, please report bugs to the issue tracker. It's API however, is to be considered alpha, meaning that future versions may break the current usage of cmd line flags, generated artifacts or other functionality.
  +NOTE: giblish shall be considered stable from a usage perspective, please report bugs to the issue tracker. It's API however, is to be considered alpha, meaning that future versions may break the current usage of cmd line flags, generated artifacts, styling or other functionality.
   
   == Dependencies and credits
   
  
positive.code: == Document ids and the reference graph
  
  NOTE: This is a non-standard extension of asciidoc. If you use this feature, you will
  need to generate your documents using giblish to make this work.
  
  giblish extends the cross reference concept in asciidoc with a _document id_ mechanism.
  To use this, you need to:
  
   . Add a `:docid:` entry in your document's header section.
   . Refer to a document using the syntax pass:[<<:docid:#DOC_ID#>>].
   . Run giblish with the -d switch when generating documents.
  
  
negative.code: a destination directory tree containing the corresponding html or pdf files
  and adds some handy tools for easier navigation of the resulting files.
  
  An example of how giblish can generate the master branch of the official asciidoc.org
  documentation git repo can be found at http://www.rillbert.se/adocorg/with_search/
  
  The added tools include:
  
   * An index page listing all rendered documents with clickable links.
   * A (stripped-down but nonetheless useful) text-search of your (html) documents (requires
     that you view your docs via a web-server.
   * If the source directory tree is part of a git repository, giblish can generate
  