tracking in idashboard should only log json-serializable objects

move setting changes in tests to override_settings

Fix course url link in enrollment emails.

Ned/fix noisy docs

We used to do it this way, I'm not sure why it was changed.
Our settings files add directories to the path, so we need to
do it here so that names will be importable.

refactor login and enrollment test cases to use the mongo modulestore

added namee to authors file

fix to problems with uploading files

Use super for calling parent __init__ methods

Refactor rake tasks for pylint/pep8

PDF textbooks in Studio

clarify LICENSE

Previously, for a textbook with only one chapter, we allowed that chapter to
not have a title -- under the assumption that it would be shown as a monolithic
textbook, instead of a chaptered textbook. However, the UI doesn't support that
idea, the code was getting a bit messy, and there was no real benefit to the idea
of not having to specify a chapter title. This commit removes that special case,
and ensures that all textbook chapters must have a name and an asset path.

They are the defaults now