Implement consistent admin interface

* Consistent route/model/controller/view layout
* Get rid of unused photos, speakers, dietchoices, social_events controllers
* Drop unused :public from Rooms and :description from CallForPapers

app/views/admin/questions/_questions.html.haml

@@ -1,10 +1,9 @@
-%h2
-  Questions for #{@conference.short_title}
-  - if @questions_conference.count
-    = "(#{@questions_conference.count})"
-%i The questions will appear in the registration page of the conference
-
-%table.table
+%table.table.table-hover#questions
+  %th Enabled
+  %th Question
+  %th Type
+  %th Answers
+  %th Actions
   - @questions.each do |q|
     %tr
       %td
@@ -12,15 +11,16 @@
         = check_box_tag "conference[question_ids][]", q.id,
                         @conference.question_ids.include?(q.id), id: dom_id(q)
       %td
-        = label_tag dom_id(q), q.title
-        %br
-        = label_tag dom_id(q), "Type: #{q.question_type.title}"
-        = ','
-        = label_tag dom_id(q), "Answers: #{q.answers.map {|a| a.title}.join(', ')}"
+        = q.title
+      %td
+        = q.question_type.title
+      %td
+        = q.answers.map {|a| a.title}.join(', ')
 
-      %td= link_to 'Edit', edit_admin_conference_question_path(@conference.short_title, q),
+      %td
+        .btn-group
+          = link_to 'Edit', edit_admin_conference_question_path(@conference.short_title, q),
                     class: 'btn btn-primary', disabled: !(can? :update, q)
-
-      %td= link_to 'Delete', admin_conference_question_path(@conference.short_title, q),
+          = link_to 'Delete', admin_conference_question_path(@conference.short_title, q),
                     method: :delete, remote: true, class: 'btn btn-danger',
                     confirm: "Delete question '#{q.title}'?", disabled: !(can? :destroy, q)