Added documentation for Constants class
Added documentation for preprocessor and fixed minor some issues
Added commons component with data location get methods
Did api changes to data locations get methods
Fixed classifier to use new data path api
Fixed classifier test classes to use new data path api
Refactored ProductClassifier
Refactored classifier to use a common file access method
Refactored to use log4j
added commons module to root pom
Added a facade class for Classifier