Pretty-print GBM model as Java.

Not ready for prime-time yet, missing a bunch of enum mappings, and any
validation
Merge branch 'master' of github.com:0xdata/h2o
updated 2.0 and 3.0 plans
Model-as-Java compiles w/javaassist & javac

Fix some syntax errors & javassist shortcomings.
Generator is more ugly, but can load generated java class now.
Still doesn't run yet... fails the verifier.
Summary2 histogram uses Scott formula again. Add unit tests.
Merge branch 'master' into summary2
REST API compatibility test.

The test is filled by REST API calls and their arguments used by
Python/R client code.
The test verifies that tests are using correct arguments published
by Java code.
REST API calls invoked from R added.

Minor changes:
 - disabling assertion

FIx of python params:
 - Prediction has prediction parameter (not predict)
 - Fix of RF parameter: class_weight should be class_weights
 - Fix of unknown 'stratify' parameter for RF
 - Fix of unknown 'doPrint' parameter passing to summary view
 - Fix of unknown 'ignore' parameter passed to PCA view
 - GLMGrid parameter beta_epsilon should be beta_eps
 - GLM has no parameter expert, only expert_settings
 - GLM typo in parameter threshold (should be thresholds)
fixed cost-lambda relationship
no categoricals in libR test
Automatically flip row to NA in PCA score if input is NA
Merge branch 'master' of https://github.com/0xdata/h2o
PostFile now contains key parameter.

Key param is kind of dummy property, since PostFile is handled directly
by NanoHTTPD.fileUpload() method. The key parameter just signalizes
that key parameter is required for the call.
emacs default heap size
Merge branch 'master' of github.com:0xdata/h2o
Check & fix Frame / Vec alignment

ValueArray conversion was making misaligned frames, forcing a lot of
network traffic.  Use a VectorGroup for all the Vecs in a converted
frame, and assert the
same vector group in Frames.
add ability to split a frame horizontally
Merge branch 'master' of github.com:0xdata/h2o
Returns a JSON error if the client send unknown param.

The H2O rejects all REST request containing unknown parameters.
This behavior can be changed by passing argument:
  -check_rest_params false
Better VectorGroup construction

Cleanup all the leaking keys & broken VectorGroup tests