Log Message:
Update to 1.66:

1.66
   - Perl-thread support contributed by Tim Brody [rt.cpan.org #31945]
   - fix [rt.cpan.org #30610] possible segmentation fault when importing nodes \ 
from a document to an element created with XML::LibXML::Element->new
   - fix [rt.cpan.org #30261] Segmentation fault when extracting elements from \ 
an XML chunk
   - make Makefile.PL require Perl 5.6.1
   - minor fixes and additions to the documentation
   - portability patch from [rt.cpan.org #29627]
   - give registered Ns declarations precedence over document-specific ones
     in XML::LibXML::XPathContext; fixes [rt.cpan.org #29650]