Log Message:
p5-Date-Manip: update to 6.73.

6.73  2018-09-01
  -  Fixed math on non-64-bit architectures
        Much of the math in Date::Manip::Base is in a 'use integer' section.
        This math can overflow in some cases in non-64-bit architectures.
        Fixed the cases where this would reasonably occur. Reported by
        Daniel Albers (GitHub #22). Also reported and tested in RT 126052.

  -  Bug in normalizing estimated business deltas
        While working on the non-64-bit issue, it uncovered a bug where
        normalizing estimated business deltas was wrong. It had never been
        reported, and it was only off by a couple seconds in some rare
        situations.