Use local links (:doc:) rather than URLs, which fixes some broken links. Update external links according to redirects, or find replacements when they are broken.
Integrate proposed changes to :ref:.
Merge pull request #76 from bgeron/flattened

Use local links (:ref:) rather than URLs, which fixes some broken links. Updates to external links.
Update epub.rst
Update epub.rst
Merge pull request #77 from jimmygilles/master

Added new EPUB3 reader entry.
Merge pull request #1 from mathjax/master

Pull from mathjax/mathjax-docs