Add 'mistune' markdown parser as an option for markdown2html
Add highlighting of GFM code blocks with mistune
Make mistune a requirement for nbconvert
Add deps for nbconvert to HTML for 'notebook' target

Also, nbconvert no longer requires Sphinx.
Integrate pass-through of mathematical expressions with markdown rendering
Version dependency on mistune
No need to install nodejs on Travis
Add support for \begin foo \end math blocks
markdown2html test doesn't rely on pandoc
Rename mistune renderer class
mistune rendering is the default
Fix code block rendering when lexer not known
Fix mathjax pass-through with mistune
Merge pull request #6028 from takluyver/markdown-mistune

Add 'mistune' markdown parser as an option for markdown2html
handle the new status messages in IPython.parallel

avoids creating implicit tasks in the Client’s metadata
and Hub’s task db when status messages arrive.
Merge pull request #6146 from minrk/parallel-handle-status

handle the new status messages in IPython.parallel
omit Nokia, update pyside link, closes #6166

Thanks @tacaswell for the report
Merge pull request #6167 from ivanov/fix-6166

omit Nokia, update pyside link, closes #6166
Merge remote-tracking branch 'upstream/master'
Added guard to reveal.js fragment/slide style options to ensure slideshow section in metadata is defined