Faster UTF-8 Validation

A while back, I received a pull request suggesting that I update the performance comparison with Encode.pm in my module, Unicode::UTF8 . When I originally wrote Unicode::UTF8 , Encode.pm used its own UTF-8 validation implementation. Since then, Karl Williamson has done extensive work improving Perl, and Encode.pm now relies on those validation routines based on Björn Höhrmann’s UTF-8 DFA decoder .