Refactored CsvParser to use a CSV parsing library (instead of parsing CSVs manually).
Improved the CsvParser: if a parsing error occurs while reading a CSV quiz file (e.g. a question is missing, an answer is missing, a correct answer was not indicated) an error message attempts to report the line and column number in the Excel file where this occurs. This message is displayed in the UI to make it easier for the quiz writer to find the problem in the quiz file. Also, added a method to scale images and avoid OutOfMmoryErrors when loading many large image files.
Added OpenCSV library.
Merge branch 'master' of https://github.com/thans/LaosTrainingApp
UI update: after completing a quiz, the user is shown a number of stars (out of five possible), in addition to their numerical score.