PROG: Added QDataStream and XML serialization capabilities to...

PROG: Added QDataStream and XML serialization capabilities to StatCumProbDistDynCalc class. Improved per coding standards. Renamed member methods and variables for clarity. Improved coding test coverage. These updates were merged from the ipce branch.

git-svn-id: http://subversion.wr.usgs.gov/repos/prog/isis3/trunk@6482 41f8697f-d340-4b68-9986-7bafba869bb8