Worked on literate output using Markdown as the text markup language.

* Added CSS based on Docco (blatantly copied).
* Updated sample text to better fit the emerging usage patterns. Some of the
  things I did to make it render nicely for the Literate output may cause
  problems when we go to render API output. I will cross that bridge when I come
  to it.
* Added parsing infrastructure to the Generator behaviour to allow a
  pre-processing pass over the document. Current the LiterateMarkdownGenerator
  is using this to compile a map of `@org` references.
* Tweaked the HTML output slightly.
* Added a layer over the PegDownProcessor in LiterateMarkdownGenerator to
  capture and transform `jlp://` links into relative links.

doc/issues/0000tn3.rst

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+Implement working internal links using ``jlp://`` schema.
+=========================================================

doc/issues/0001tn3.rst

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+Implement language-specific code parsing and comprehension.