Log Message:
Update ruby-kramdown to 1.9.0.

kramdown 1.9.0 released

This release contains some minor updates and bug fixes.

Changes

  * 3 minor changes:

    - The Rouge syntax highlighter can now be enabled/disabled for spans
      and/or blocks and options can now be set for both spans and blocks as
      well as only for spans or only for blocks (fixes #286, requested by
      Raphael R.)
    - Setting the ‘footnote_backlink’ option to an empty string now
      completely suppresses footnotes (fixes #270, requested by Kyle Barbour)
    - New converter HashAST for creating a hash from the internal tree
      structure (fixes #275, pull request by Hector Correa)

  * 1 bug fix:

    - When using the ‘hard_wrap’ option for the GFM parser, line numbers
      were lost (fixes #274, pull request by Marek Tuchowski) Published on
      Saturday, 04 July 2015