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/conference/edit.html.haml

@@ -1,17 +1,22 @@
 .row
   .col-md-12
-    %ul.nav.nav-tabs{'role'=>'tablist'}
-      %li.active
-        %a{'href'=> '#show', 'role'=>'tab', 'data-toggle'=>'tab'}
-          Show
-      %li
-        %a{'href'=> '#edit', 'role'=>'tab', 'data-toggle'=>'tab'}
-          Edit
-%br
+    .page-header
+      %h1 Basics
+      %p.text-muted
+        The most basic settings of your conference
 .row
-  .col-md-12
-    .tab-content
-      .tab-pane.active#show
-        = render partial: 'edit_show'
-      .tab-pane#edit
-        = render partial: 'edit_form'
+  .col-md-8
+    = semantic_form_for(@conference, :url => admin_conference_path(@conference.short_title),:html => {:multipart => true}) do |f|
+      = f.input :title, :hint => "The full title of the conference, e.g. 'openSUSE Conference 2014'"
+      = f.input :short_title, :hint => "A short title, e.g. 'oSC14', to be used in URLs"
+      = f.input :description, hint: markdown_hint('A description of the conference.'), input_html: { rows: 5, data: { provide: 'markdown-editable' } }
+      = f.input :color, :hint => "The color will be used eg for the dashboard.", :input_html => {:size => 6, :type => "color"}
+      - if !@conference.logo.blank?
+        = image_tag @conference.logo(:thumb)
+      = f.input :logo, :label => "Conference Logo", :hint => "This will be displayed on the front page."
+      = f.inputs :name => "Scheduling" do
+        = f.input :timezone, :as => :time_zone, :hint => "The conference time zone"
+        = f.input :start_date, :as => :string, :input_html => { :id => "conference-start-datepicker", :readonly => "readonly"  }
+        = f.input :end_date, :as => :string, :input_html => { :id => "conference-end-datepicker", :readonly => "readonly"  }
+      = f.action :submit, :as => :button, :button_html => {:class => "btn btn-primary"}
+