Mechanize: Spit out 'X-Died' error, if present.
    This exposes failures caused by "twitter:card" meta infestation
Test url: http://www.bbc.co.uk/news/uk-politics-16509892
To fix: upgrade to HTML-Parser-3.71
Merge pull request #142 from atomicdryad/whinemore

Mechanize: Spit out 'X-Died' error, if present.