XXX - PoC Support for Advanced analytics in Spring XD.

Refactoring of AnalyticalModel infrastructure.
XXX - PoC Support for Advanced analytics in Spring XD.

Refactoring of AnalyticalModel infrastructure.
Added prototypic interface to R via command-line.
We now generate PMML directly from an R script that provide a set of well-known functions that can be called by passing an appropriate argument via the command-line.