Changed coefficient representation to be sparse in GLM if the number of predictors is greater than given threshold(default is 1000)
GLM2 fix: fixed bug in scoring when lambda_search was on (or use_all_factor levels was on), scoring was still skipping 0-levels and shifting the rest to the left -> scoring was completely incorrect for categoricals.

Fixed by adding explicit check whether 0 levels are to be skipped.
Glm2 fix: fixed AIOB when running with lambda search and line search (vector resize was wrong).
Added lambda_min param to glm2. It is to be used with lambda_search, specifies minimal lambda as a ratio of lambda_max.
GLM2: Added option to set best lambda from the ui.
Rename error to errorr to get R tests to pass.

The R __remoteSend method is doing a blanket check for a entry named 'error'
in the response.
The commit hides tree keys of tree builders.
Fixed double import issue in import from S3 and Hdfs (same problem as in nfs case: frame needs to be created and locked empty, than updated with the new filevec).
Merge branch 'master' of github.com:0xdata/h2o
Catch broken custom serializers & report
Removed the logic in FileIntegrityChecker which was removing previous keys. FileIntegrityChecker used to remove LOCAL keys matching the same path.

Replaced by removing only exactly the inserted (frame) keys, both local and remote.
Bugfix in hdfs/S3 import. Typo, was passing in key k2 instead of k.
Added more detailed fail message when doing nfs import and file is missing on some nodes, both to R and UI. R side added only displays it as a warning for now.
some typos in the last set of updates for test.0xdata.com
re-adding the objective function test
Restrict binary operations involving H2OParsedData objects to scalar numeric and logical R values only
Fix some typos in getting GBM prediction with H2O data
GBM Regression & Bernoulli add initial prediction

Model was built fine, but the scoring failed to add back the initial
prediction - so e.g. for regression the prediction was off by the mean.
Get crazy on checking the regression results

...also turn back on all the other GBM tests
Allow more bins in the top-levels of DRF & GBM

As the levels get deep & bin-counts become costly, shrink bins used to
the user-limit.  Cleanup leaked keys & IdeaJ warnings in GBMTest.
Golden DRF tests uniformly better.