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/proposal/new.html.haml

@@ -1,7 +1,28 @@
 .container
   .row
     .col-md-12
-      = simple_format(@conference.call_for_papers.description)
+      %p
+        - if @conference.event_types.any?
+          You can submit proposals for
+          = "#{event_types(@conference)}."
+        - if @conference.tracks.any?
+          Proposals should fit in one of the
+          = "#{pluralize(@conference.tracks.count, 'track')}:"
+          = "#{tracks(@conference)}."
+        The submission period has begun
+        %em
+          = @conference.call_for_paper.start_date.strftime('%A, %B %-d. %Y')
+        and closes
+        %em
+          = @conference.call_for_paper.end_date.strftime('%A, %B %-d. %Y.')
+        That means you have only
+        - days = (@conference.call_for_paper.end_date - Date.today).to_i
+        %b
+          = pluralize(days, 'days')
+          left!
+        Remember
+        = @conference.short_title
+        will only be as good as the sessions you present. Submit early, submit often!
   .row
     .col-md-12
       = render 'proposal_form'