Converting "Problem" to a shared_ptr
refs #4009, #3698
Converting "Executioner" to a shared_ptr
refs #4009, #3698
add new water_steam_eos interface to control convergence tolerance which Ref. #4033
Merge pull request #4031 from permcody/problem_ptr

Converting "Problem" to a shared_ptr
Merge pull request #4034 from liuwenf/update_water_steam_eos_4033

Update water_steam_eos moduel #4033
Merge commit '6a09162e7150abb3359f3c501435bdb20ebffdbb'