Add missing callback functions.
Fix bugs in entity info definition.
Rename questionType.provider => questionType.plugin.
Add quiz_question_update_7603() to create new tables for question and question type entities.
Question type management page - /admin/structure/quiz-questions.
Fix default value in question type form is not correct.
Fix wrong label for question entity.
Fix warnings on /admin/content/quiz-questions page.
/admin/content/quiz-questions should be a local task.
On question type module enabled, create new default bundle for question entity.
Define /quiz-question/add landing page
Fix bug in question entity definition.
Define basic structure for /quiz-question/add/%
Clean up quiz_entity_adding_page().
Rename _quiz_question_get_instance() to quiz_question_get_plugin() and clean it up.
$question param of quiz_question_get_plugin() should not be an array.
Simplify quiz_question_get_plugin().
Update quiz_question_get_plugin(), change $use_cache param to $refresh.
misc
Revert "Update quiz_question_get_plugin(), change $use_cache param to $refresh."

This reverts commit c42c0607cf54b57a8f58177fe7979f3d57a0ff11.