devilry_qualifiesforexam_approved: Updated for Django 1.6.

See #497.
devilry_qualifiesforexam_points: Load url from future for Django 1.4

compatibility.
devilry_qualifiesforexam_select: Updated for django 1.6.

See #497.
authenticate...login.django.html: Import url from future.

For Django 1.4 compatibility.
devilry_student: Updated for Django 1.6.

See #497.