Added default sorting.
Added logging
Minor changes to client
Made null keys ok.
Fixed type of messages.
Merge pull request #112 from Cal-CS-61A-Staff/check_version

Check version
Merge pull request #110 from Cal-CS-61A-Staff/course_frontend

Added tests. Cleaned up code. Added courses to the frontend.
Fixed wrong user model error.
Merge branch 'release' into view_code
undid changes
https
removed json