removed starting instruction removal when initializing quiz
changed prepareQuiz function so it doesn't return anything anymore - it just modify document object
refactor: simple functions extraction
refactor: extracted addQuizLine function
refactor: moved all interactive quiz functions to separate file
refactor: imporved select query readability
refactor: moved get_objects_of_query_results function to quiz_interactives; renamed generateRandomIndex to randomIndexGenerator
refactored quiz to simple module pattern (Crockford)
some misspelling/mistakes fixes
added coments for future
Merge branch 'refactor/quiz' into develop