Add more options for surveys

* Survey period constraints
* Add abilities
* Enforce required questions
* Update survey_submssion updated_at
* Do a full match of possible answer and user reply

app/views/surveys/show.html.haml

@@ -10,15 +10,19 @@
         = @survey.start_date
         to
         = @survey.end_date
-
+        - unless @survey.active?
+          %label
+            %i.fa.fa-exclamation-circle
+            This survey does not accept replies at this monent.
 .row
   .col-md-12
     = semantic_form_for @survey_submission, url: reply_conference_survey_path(@conference.short_title, @survey) do |f|
       - @survey.survey_questions.each.with_index(1) do |survey_question, question_index|
         .row
           .col-md-10.col-md-offset-1
-            - survey_reply = survey_question.survey_replies.find_by(user: current_user) || SurveyReply.new(survey_question_id: survey_question.id, user_id: current_user.id)
+            - survey_reply = survey_question.survey_replies.find_by(user: current_user) || SurveyReply.new(survey_question_id: survey_question.id, user: current_user)
             = render partial: 'admin/surveys/survey_question', locals:  { survey_question: survey_question, question_index: question_index, survey_reply: survey_reply }
+
       .row
         .col-md-10.col-md-offset-1
-          = f.submit 'Submit', class: 'btn btn-primary pull-right'
+          = f.submit 'Submit', class: 'btn btn-primary pull-right', disabled: !(can? :reply, @survey)