[Stable] Final slow version

-Modified TestResults class
-Fixed a design issue where label mapping was done while extracting
vocabulary
-Changed accuracy in TestResults to float from int
-Removed read_files() call from constructor of FileReader
-Removed label setting in Naive Bayes Classifier where after
classifying the document, the new class is assigned to the feature
vector
-Added multiple inclusion protection to header files
-Fixed warnings due to calls to print functions
-Added TestData.txt file
-Renamed DocumentClassifierData to TrainingData.txt