Upstream changes:

1.9719 [2009-01-04]
- As with QNX, Haiku has the API of interval timers but not
  the implementation (bleadperl change #34630), hence skip
  the tests, via David Mitchell.

1.9718 [2008-12-31]
- .xs code cleanup from Albert Dvornik
- in the #39 and #40 do not do us I did, mixing alarm() and
  sleep().  Now instead spin until enough time has passed.

1.9717 [2008-12-30]
- Skip the tests added in 1.9716 (#39, #40) if there's no subsecond
  alarm capability, like with the older subsecond alarm tests

1.9716 [2008-12-26]
- Change documentation to agree with reality: there are
  no interval timers in Win32.
- Address [rt.cpan.org #35899] (problem in subsecond sleeps),
          add two tests to guard against this problem
- Address [rt.cpan.org #36600] 'Division by zero' failure in test suite
- Address [rt.cpan.org #37340] [PATCH] Address timer process in test
- Address [rt.cpan.org#40311 ] bad implementation of hrt_usleep
          with TIME_HIRES_NANOSLEEP

(sno)