Another round of splash design

* Add map to splash
* Reverse venue<->conference relation
* Split venue address into fields
* Don't go through venue for lodgings anymore

db/migrate/20141118150427_cleanup_venue.rb

@@ -0,0 +1,7 @@
+class CleanupVenue < ActiveRecord::Migration
+  def change
+    change_column :venues, :name, :string
+    remove_column :venues, :offline_map_url, :string
+    remove_column :venues, :offline_map_bounds, :string
+  end
+end