class TTimeStamp

 The TTimeStamp encapsulates seconds and ns since EPOCH

 This extends (and isolates) struct timespec
    struct timespec
       {
          time_t   tv_sec;   /* seconds *
          long     tv_nsec;  /* nanoseconds *
       }
    time_t seconds is relative to Jan 1, 1970 00:00:00 UTC

 No accounting of leap seconds is made.

 Due to ROOT/CINT limitations TTimeStamp does not explicitly
 hold a timespec struct; attempting to do so means the Streamer
 must be hand written.  Instead we have chosen to simply contain
 similar fields within the private area of this class.

 NOTE: the use of time_t (and its default implementation as a 32 int)
       implies overflow conditions occurs somewhere around
       Jan 18, 19:14:07, 2038.
       If this experiment is still going when it becomes significant
       someone will have to deal with it.