Import of PEVANS/IO-Async-0.64 from CPAN.

gitpan-cpan-distribution: IO-Async
gitpan-cpan-version:      0.64
gitpan-cpan-path:         PEVANS/IO-Async-0.64.tar.gz
gitpan-cpan-author:       PEVANS
gitpan-cpan-maturity:     released