Pass a number of functions to the theme

This is a big patch to try and separate functionality from display. The biggest changes revolve around moving most markup out of hooks and callback functions and into theme functions. Here is the list of new theme functions in quiz.module:

• theme_quiz_admin
• theme_quiz_admin_summary
• theme_quiz_feedback
• theme_quiz_getuser_results
• theme_quiz_progress
• theme_quiz_question_table
• theme_questions
• theme_quiz_take_question
• theme_quiz_take_summary
• theme_quiz_user_summary
• theme_quiz_view

The following functions were added to multichoice.module:

• theme_multichoice_form
• theme_multichoice_render_question

Here is a quick list of functionality changes that accompany these changes:

• There is now a quiz.css file that is getting added to the page output in quiz_menu()
• The admin "quizzes" page no longer calls system_settings_form().
• The quiz results pages (summaries) have been simplified to allow for longer questions and longer blocks of questions feedback. Generally, this is where the most rewriting happened in order to break up the quiz_get_results_table function.
• The progress indicator is now a simple "Question x of y" display, but note that it can easily be themed to be a more elaborate graphic.
• Moved all theme functions to the bottom of the module so they are grouped together.

There are still some issues with the html, etc., but I wanted to leave as much of that for other patches in order to keep this already large patch focused. Hopefully this will be the last big restructuring of the code for a while.

Give it a go and let me know if I missed anything.

Committed to head.