add a JsonDiff class. Fix the test_rf_big1_nopoll.py that does many parallel H2O RF (wasn't checking the results correctly)..JsonDiff the results and print. Vary seed= otherwise results don't change (other than the model name I provide)
rf fvec needs real for sample_rate ..was sendd 0 which caused the stack trace.
Merge branch 'master' of github.com:0xdata/h2o