Change in order of output to analyze_pofd_coverage, other minor fixes.

* Order that analyze_pofd_coverage outputs things is the order
  they were read in, which includes the ability to repeat sets.
* Change splitpoint marginalization over 2nd dimension in
  PDFactoryDouble::findSplitPoint.  It is much faster this way.
* Properly write isLog in PD/PDDouble to HDF5 (needed to be
  converted to hbool_t)