Test split.
Small utilities.
Shuffle task to randomize a vector.

Shuffle is dummy and permutates only data inside the chunk.
Computing votes per tree.
updated
Change default to master.
wip for drf2
Merge branch 'master' of github.com:0xdata/h2o
Small bit of utilities.
Other small utilities.
Fix of NPE in DRFProgressPage.

Progress page was faster than code preparing a first initial version
of model. Hence, the progress page hits NPE sometimes.
DRF2 renamed to Random Forest, Random Forest renamed to DRF1.
Corrected scoring for DRF.

Classification produces distribution of votes with sum = 1.
Regeression produces an average of predictions of all trees.
DRF parameters.
Fix of preparing wrk_cols for regression.

Regression wrk col now contains a copy of response.
Corrected computation of total rows coming into given leaf.
Removed debug prints and asserts.
Fixed typo in using argument for HTML generation.
Renaming of distributed operation used to compute individual tree votes.
Merge remote-tracking branch 'origin/master' into drf2