Multiple Choice w/ Rationale

These are the changes for the new multiple choice questions which prompt the student for a rationale for each option chosen.

Enables in authoring, OTrunk Runtime, and reporting:
 - Authoring and OTrunk Runtime:
   -- multiple selection questions (checkboxes, does not require an updated jnlp)
   -- rationale prompts on either style of question (radio buttons or checkboxes - requires jnlp 20130117.211006 or later)