Prevent self-induced page truncation with twitter headers and old HTML::Parser

Issue: Any page with 'twitter:card' meta headers will be truncated. get_flash_videos will
    complain that it can't find a video, while neglecting to mention this.
Test url: http://www.bbc.co.uk/news/uk-politics-16509892
Affected distributions: Optware, Debian Squeeze, and likely alot of embedded linux devices
    where fetching the latest from cpan is not possible locally, and requires a dev environment
    with a cross-compiler and workarounds.
Upstream culprit: ancient HTML::Parser library. 3.71 fixes this.
Caveat: This disables the standard LWP behavior of sticking meta headers into the http headers
    hash. From what I can tell, this should have no adverse consequences ('meta name="location"' is invalid.)

See also:
https://github.com/libwww-perl/http-message/issues/3
https://rt.cpan.org/Public/Bug/Display.html?id=85119