Tiny formatting change
Refactored some of the code in grade() to helper functions.

Conflicts:
	lms/djangoapps/courseware/grades.py
Added test for grades.py to make sure that the grader plays nice with abtests.
More refactoring.

Conflicts:
	lms/djangoapps/courseware/grades.py
Added TestFindShouldGradeSection. All tests currently pass.
Added docstring to find_should_grade_section helper method
Added TestFindAttempted, all tests currently pass.
added docstring for find_attempted
Rebase fix.
Added docstring to TestFindAttempted
Removed old argument related to projected grades`
Reverted accidental deletion of line.
Added test for grades.grade
Added TestGetScore with first few methods. Deleted old print statements from earlier tests. Renamed fake_key to key in earlier tests.

Conflicts:
	lms/djangoapps/courseware/tests/test_grades.py
Finished with TestFindAttempted, all tests pass.
Fixed a test in xmodule.graders.
Added docstring to compute_graded_total
Fixed tests to remove references to attempted
Removed references to attempted
Removed newlines before docstrings