Robustify hoop_stress test closes #3633

Converge tighter, loosen up stress tolerances a bit, use inexact Newton
to speed it up a bit, remove setting of pc_hypre_boomeramg_strong_threshold.
Merge pull request #3716 from bwspenc/fix_tests2

Robustify hoop_stress test
Merge commit '7af85d0071dd478b6fedce3b56985387b61b67c5'