fix following redirects
Merge pull request #5826 from romeotheriault/fix_follow_redirects

A fix for uri module regarding following redirects. The old behavior would follow redirects either way. This change clarifies the functionality and makes it a bit more explicit. Comparing the old behavior to the new 'yes' == 'all', 'no' == 'safe' and now 'no' will not follow any redirects. Historic behavior is still supported and documented with a push to the new values.