Rename getNodeForm -> getEntityForm.
Rename QuizQuestion class to QuestionPlugin.
Remove unneeded code.
Fix #89: Created question is not linked to quiz.
Update comments.
misc
Rename QuestionPlugin->node => QuestionPlugin->question.
Clean up QuestionPlugin::getEntityForm().
misc
Cleanup QuestionPlugin::saveRelationships().
Use Entity class for question relationship entity.
Revert "Cleanup QuestionPlugin::saveRelationships()."

This reverts commit 0e8352c0ada5c154ca9a0ea1bcd3fe3b152e18c0.
Fix broken test cases.
Super small changes in DEVELOPER.txt
Remove quiz.doxy
Add QUESTION_CATEGORIZED_RANDOM constant.
Make QuizHelper::updateMaxScoreProperties() less dangerous.
Rename QuizHelper::updateMaxScoreProperties() to updateMaxScoreProperty().
QuestionForm class is no longer needed.
- in path instead of _.