1) included code to read qr from four 90 degree rotations for improved robustness of read
2) exlarged the region to read qr codes from. This is a delicate balance between excluding irrelevant text that may confuse the qr code reader and
cutting off pieces of the qr code that have been wobbled by the scanner
3) included code for manual entry of the filenames for student's quizzes that cannot be deciphered by the qr code reader
