Use new ReBalanceDataSet helper in DeepLearning.
Merge branch 'master' into arno-deeplearning2
Use asyncExec for DeepLearningTask2 to avoid raising the thread priority.
Cosmetics.
Fix NPE in rebalance call.
Use -1 to indicate processing all the data per node.
Merge branch 'master' into arno-deeplearning2
Merge branch 'master' into arno-deeplearning2

Conflicts:
	src/main/java/hex/deeplearning/DeepLearning.java
Merge branch 'master' into arno-deeplearning2

Conflicts:
	src/test/java/water/fvec/RebalanceDataSet.java
Use new API for ReBalance.
Merge branch 'master' into arno-deeplearning2
Merge branch 'master' into arno-deeplearning2
Add sparse matrices and vectors.
Merge branch 'master' into arno-deeplearning2
Re-enable random parameters for DeepLearning vs NeuralNet comparison.
Use new API for void execImpl().
Increase tolerance.
Make checkpointing compatible with new JobState assertion check.
Cosmetics: Use DenseRowMatrix and DenseVector for DeepLearning.
Fix checkpointing number of epochs and auto-set the classification bit.