Fix link
Fix links to glossary at book.html

Originally the glossary is available at
http://software-carpentry.org/v5/gloss.html but for
http://software-carpentry.org/v5/book.html it is already
available at the same page. So we could change the links
pointing to glossary to the book.

This change is necessary to to avoid problems when creating
the EPUB and PDF version of our lessons.
Update IPython Notebook template

- Improve to handle err class
- Improve pandoc support
Update Markdown from IPython Notebooks

Update Markdown files based on previous commit changes at template.

Built with

    $ python --version
    Python 2.7.7
    $ ipython --version
    2.1.0
Workaround for colspan and vertical headers
Change some anchors to enable EPUB post processor
Add epub entry to Makefile

- Makefile for EPUB
- Metadata for EPUB
- CSS for EPUB
- Post-processor for EPUB building stack

  When converting HTML to EPUB using pandoc we lose the
  anchors at glossary.  This PR add a post-processor to
  restore this anchors.

  This close #550.