Add threshold, banner and badge to course model
Users api, api key settings-based authorization
Return only the passed courses in the nested resource
Badges application

Automatically award the completion badge of a course to the user when
he enter in his transcript if he has successfully completed the course.
Add a button to ask for a certificate of completion
Badges models name spanish translations
Show an url to the image so people can use the badge somewhere else
New transcript system, the normal units no longer count

Add a setting to choose which courses use the old qualification method
where the normal units counted too for the final mark.
Remove the theme images from the transcript view
Fix some bugs: threshold problem, Zero division
New celery script
Improved badget app (user_badgets, user_baget). Remake transcript view
Improve id/email resolution
Now the tastypie API for calculate allcourses and passedcourses admits user_id or user_email
Improve search of users in the admin interface
Forgotten files (badget templates)
Merge branch 'feature-payments' into feature-teachers-administration

Conflicts:
	moocng/api/authorization.py
	moocng/api/resources.py
	moocng/api/urls.py
	moocng/courses/admin.py
	moocng/courses/utils.py
	moocng/courses/views.py
	moocng/locale/es/LC_MESSAGES/django.mo
	moocng/locale/es/LC_MESSAGES/django.po
	moocng/settings.py
	moocng/static/img/cert_banner.png