Clear results when answer is changed.

This changes the interaction when user changes results after having submitted them for the first time:

-  When a user first gets to an MRQ or MCQ they see the question and list of options, and the SUBMIT button is in disabled state. (no change)
- When the user makes their selection(s) the SUBMIT button becomes active. (no change)
- When the user hits the SUBMIT button, the icons appear to the left of the answer choices, the Feedback popup appears, the feedback text below the question appears, and the SUBMIT button is back to disabled. (disable the button upon submit)
- When/if the user makes another choice, the act of selecting that choice closes the feedback popup, removes the feedback below the question, removes the icons to the left of all answers, and changes the SUBMIT button to an active state. (clear out answers and activate submit button)
- When the user hits the SUBMIT button, the icons appear to the left of the answer choices, the Feedback popup appears, the feedback text below the question appears, and the SUBMIT button is back to disabled. (disable the submit button again)