Add in Feed Forward Neural Network to ABAGAIL

The changes herein include:
- Adding theJenix's feed-forward neural network code into the library itself (func.nn package)
- removed the bin directory (no reason to be syncing the compiled class files in my opinion)
- DataSetReader is now an abstract class; it currently has one child class (CSVDataSetReader) which contains the code that was originally DataSetReader. More children (such as an ARFFReader) could be built with ease