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

Refactor addPostprocessor
Merge commit '9bd3807ad828043e042b5c111290d5c0a88d7216'
Restricting test
refs #2835
Merge pull request #2891 from permcody/skip_test_2835

Restricting test
Merge commit 'a8bad0caf9d7bba3a7519efa8ce68ce05ac9e523'