PackageIndex._download_html (setuptools/package_index.py) attempts to detect if
an HTML page is a Subversion repository using the regular expression
r'<title>Revision \d+:'. This breaks for Sourceforge subversion repositories,
which include the project name before the "Revision" text (see
http://cctools.svn.sourceforge.net/svnroot/cctools/vendorlibs/utidylib/ for an
arbitrary example).