added tests

added users_completed

added users_not_started

and users_grade_average float conversion exception when average is None

avoid auto round by casting denominator to float

Conflicts:
	lms/djangoapps/api_manager/users/tests.py

uncomment discussion stats call

relabel migration at 0008

Increase column size of document_url field; url returned by provider may be very long, especially if filename is quite long

to skip leaders list for home page call

in courses list to get courses by id