Fixed bug which caused issues with creating test instances in API.
Resulted in a slight increase in accuracy on train/test classification.
Fixed a bug which caused accuracy to drop when attempting to parallelize
creation of test Instance objects
Fixed some bugs in calcInfoGain and applyInfoGain. both now return
double[][] and applyInfoGain takes a double[][] instead of a
list<Integer> like it used to. Also updated some documentation a bit and
cleaned up some code.
Documented the InstancesBuilder in preparation for creating the next
layer/SimpleAPI