save report by options, expected, score, mixed

There has three options.

a. expected: final_score = max(expected, score)
b. score: final_score = score
c. mixed: show mixed values (score/expected:gap)

For example,

Expected:
Based on the observation, expected scores are almost similar to
calculated scores. So, 'expected' is good option for compensating scores
due to grading script errors or broken markdown by student.

Score:
Just show calculated scores. You might want to check score '0' values
because it means they had some calculated errors due to broken
markdown by student.

Mixed:
It shows you a set of scores, calculated score, estimated score, gap.
For example,

100/98:2S : calculated score 100, estimated score 98, gap 2, S means
calc one is bigger.

54/60:6E : calc score 54, estimated score 54, gap 6, E means estimated
score is 6-point bigger

0/100:100E : calc score 0 means it had calculation error due to some
reasons. So, you need to check it manually.