Log Message:
Update to 1.16

Upstream ChangeLog:
1.16
    [TEST FIX]
    - 1.15 breaks AIX fix on 1.14.
      t/05_sigint.t skips on perl <= 5.8.8.

1.15

    [TEST FIX]
    ${^CHILD_ERROR_NATIVE} is only available in perl 5.8.9 and later.
    (kazeburo++)

1.14
    - Fixed testing issue on AIX.
      https://rt.cpan.org/Public/Bug/Display.html?id=72779
      (w.phillip.moore)
    - depend to Test::SharedFork 0.19 for better TB2 support
      (tokuhirom)