PUB-837: Move logging to execImpl.
Merge branch 'master' of https://github.com/0xdata/h2o-dev
Merge branch 'master' of https://github.com/0xdata/h2o-dev
PUBDEV-9: Port over DeepLearning as of h2o 8d2b7efa667d3.
Compiles, but tests are still failing (remain disabled).

Notes:
Added helpers to Vec/ArrayUtils/PrettyPrint/Frame.
Also made minor changes to Model/KMeans (mostly scoring related).
Merge branch 'arno-deeplearning'