Local engine

Moved the local engine to a separate module, added an option to the samoa script to deploy to local.
The documentation and the 5-minutes tutorial need to be updated to reflect the changes.
Now we have a third deployable jar in target/SAMOA-Local-0.0.1-SNAPSHOT.jar and it already includes a simple logging library.
To run the example the command line is now:
src/main/resources/samoa local target/SAMOA-Local-0.0.1-SNAPSHOT.jar "PrequentialEvaluation -l classifiers.trees.VerticalHoeffdingTree -s (ArffFileStream -f covtypeNorm.arff) -f 100000"