Release Notes 1.4.6

Bugfixes and improvements: - Cleanup lots of old examiner UI code. - https://github.com/devilry/devilry-django/issues/536 - https://github.com/devilry/devilry-django/issues/538 - https://github.com/devilry/devilry-django/issues/539 - https://github.com/devilry/devilry-django/issues/549 - https://github.com/devilry/devilry-django/issues/547