WIP
Overhaul the perrier functionality

H2OContext becomes static class, not needed in most places.  Has
utilities to convert RDD & SchemaRDD -> DataFrame
H2ORDD only supports DataFrame -> lazy RDD.  No longer converts RDDs ->
DataFrames
Renaming
Finish up prostate demo

In & out of spark RDDs, plus SQL, plus an algo
Missing dependency on h2o-scala in h2o-perrier pom.xml
From typed RDD to a data frame.
Deep learning example revisited.

 - scoring return a data frame
 - prediction is validated on generated data