stop filling the logs
fix reset for latest 3.091r course xml changes

Recent updates to policy.json in 3.091r course xml changed the grade
data structure returned by edX from:

{'totaled_scores': {'Assessment': [obj, obj, obj, ...]}}

to

{'totaled_scores': {'Assessment1': [obj], 'Assessment2': [obj], ...}

Updated module_tree_reset code to aggregate all of the assessment
objects in this case.