Replace addPostprocessor(std::string, Real, ...) with addParam<PostprocessorName>(std::string, Real, ...)
refs #2879
Merge pull request #2890 from permcody/param_refactor_better

Refactor addPostprocessor
Restricting test
refs #2835
Merge pull request #2891 from permcody/skip_test_2835

Restricting test