Open up a kramdown class to convert inline code more intelligently

[Delivers #62819586]
Issue pull request for branch 62819586-inline-codespan

[Delivers #62819586](https://www.pivotaltracker.com/story/show/62819586)
[#62819586]

* 62819586-inline-codespan:
  Issue pull request for branch 62819586-inline-codespan
  Open up a kramdown class to convert inline code more intelligently
  Bump version number
  Issue pull request for branch utf-8-62519814
  Add support for UTF-8 in title, etc., & custom chaptername
  Add support for tabularx environments
  Polish
  Bump version number
  Issue pull request for branch doublebackslash-62685096
  Add support for \\ in Markdown
  Bump version number
  Issue pull request for branch 62668410-pdf-png
  Support PDF images in PDF output, PNG otherwise
  Bump version number
  Issue pull request for branch unicode-highlight-cache-62434202-62433730
  Escape, yet again, some gorram backslashes
  Fix the failing test
  Add failing test for weird code
  Unpack with the right encoding
  Write failing test for Unicode highlighting