Summary: Sphinx extension to redirect nonexistent pages

Description:
This sphinx extension redirects non-existent pages to working pages.
Rediraffe can also check that deleted/renamed files in your git repo are
redirected.

Rediraffe creates a graph of all specified redirects and traverses it to
point all internal urls to leaf urls. This means that chained redirects
will be resolved. For example, if a config has 6 chained redirects, all
6 links will redirect directly to the final link. The end user will
never experience more than 1 redirection.

Note: Rediraffe supports the html and dirhtml builders.

Maintainer: daviddavid