Converted db_insert/update to entity_save to save code.
Updating _quiz_is_last_question to check for a last page as well. Adding page navigation to quiz taking.
Do not set qnr_id if it is a new revision (meaning new relationships will be defined). Note that this really screws up parent/child relationships currently.
Replacing question browser with Views and VBO.
API CHANGE: simplifying quiz_get_questions()
Add missing quiz_get_sub_questions().