adds in aria attributes and semantic status content for choicegroup problems

common/lib/capa/capa/templates/choicegroup.html

@@ -28,10 +28,11 @@
             %>
             % if correctness and not show_correctness=='never':
             class="choicegroup_${correctness}"
+            <span class="sr" aria-describedby="input_${id}_${choice_id}">Status: ${correctness}</span>
             % endif
             % endif
             >
-            <input type="${input_type}" name="input_${id}${name_array_suffix}" id="input_${id}_${choice_id}" value="${choice_id}"
+            <input type="${input_type}" name="input_${id}${name_array_suffix}" id="input_${id}_${choice_id}" aria-describedby="answer_${id}" value="${choice_id}"
             % if input_type == 'radio' and ( (isinstance(value, basestring) and (choice_id == value))  or  (not isinstance(value, basestring) and choice_id in value) ):
             checked="true"
             % elif input_type != 'radio' and choice_id in value: