Change the Time constraints to use the limits of a 32-bit system

* This change is the most cross platform compatible change, and if
  limits are hit it should be possible to define different limits
  for different kinds of systems.

  I did some basic research and it appears that different rubies
  have different limits. I could not get any consensus about what
  the limits are, if any. Ideally there would be a formula that
  could be used to determine the platform specific limits; but I'm
  guessing that it will need to be specific using conditional logic
  or a case statement at best.

  For now, default to the lowest common denominator until it becomes
  an issue or per-platform limits are known.
Change DateTime fractional seconds to be picoseconds