Renamed CSVGetter to CSVHandler, added methods.
Class now contains overloaded readCSV() method for extracting data from
CSV file (with String filepath or File object) and storing it in
ArrayList<String[]> or String[][].
Also has boolean to track whether instance actually has data available
for outputting.
toArray() and toArrayList() methods currently return previously
mentioned variables.
Static method getExtension(String) returns the file extension of a given
filepath.