Fixed potential zero division with a divisor check. Added an additional assert (see the comment above the assert). Fixed late submission penalty calculation.
If the assessment service does not set the obligatory max_points, the response is considered erroneous. Also some cosmetic changes. Also, moved the get_course_instance method from BaseExercise to LearningObject.
Merge commit 'd8343db9926befdaa509d4e982c2c62585971e4b'

Conflicts:
	urls.py

There was actually no conflict but some whitespace difference messed things up. Teste
Added error handling for failing post data validation in the async submission callback view. It's very cool.
Merge branch 'course_module_points'

Conflicts:
	exercise/submission_models.py

Some weird whitespace merge conflict. Ran automatic indention converter (level = 4 spaces) just in case.
Cosmetic changes.
Merge pull request #62 from Rubinous/master

Fixed potential zero division with a divisor check. Added an addition…