grouped the comparison comments by answerpairings and users

- this ws done so that we can group all the evaluations for each user
and anser pairing in one div tag, for the following reasons
	- avoid repeated information - eg. feedback to answers
	- group the comparisons together to be just like how the
	students submitted the evaluation
	- simplify counting the number of evaluations completed.
		- eg. one submission with two criteria will be counted
		as 1 instead of 2.
- We can access the common attributes between the comparison comments
for the same answer pair and user by accessing the first object of each
group (by answerpairing_id)
fixed evalcomments backend test

- The tests broke due to the slightly refactored structure of the
results