Cleanup of D3Plot code.  TODO: add log scale, etc.
Merge branch 'master' into arno-deeplearning
Merge branch 'master' into arno-deeplearning
Perform all NN math in double precision, also store everything but the weights
and the weight momentum in double precision (those remain float arrays).
Re-enable NN Iris test. Now leads to identical results (<1e-15 abs error) for
single-threaded. Also added multi-threaded test, but not expecting agreement
there because of Hogwild.  Instead, compute the MSE of weights and print a
message every time there is a Hogwild induced difference in classification accuracy.

Data types between H2O and the reference implementation now match:
Use double for everything but the weights (and the weight momenta).

Also allow the Threaded trainer to take an argument for the number of threads.
Remove unneeded cast.
Merge branch 'master' of https://github.com/0xdata/h2o