Added an exit survey on the profile page. It can be answered once, either directly or through a certificate request.

Certificate request form is now only submitted once. The link shows if a certificate can be downloaded, or is still being generated.

Added UUID generation to certificates. Now, each student/course will have a unique ID for verifying the certificate.

Moved certificate requests to its own application. Fixed up styling on certificate request form. Changed wording of the form.

Added a form on the profile page to request a certificate. Still needs major styling, but the basic back-and-forth works.

Moved potential failure outside of unrelated try/catch block that would have masked the missing settings.DATA_DIR

Catch Exception instead of ValueError for accessing our general content cache -- exception thrown changed in django 1.4

Fixed zero-score-possible bug.

fixed the default weight to not interfere with precedent

Course settings are now defined in DATA_DIR/course_settings.py. Used by importing courseware.course_settings. The grader is defined in these settings files.

added weighting system for the midterm

It'd be nice to move the Score.__sub__ as we discussed, but that shouldn't hold up merging the rest so it can be put on the staging environments and tested more thoroughly.