Fixes for voting on proposals. 0 for no voting option. Set default value in migration to avoid blank/null problems.

db/migrate/20131228132353_change_default_rating_in_call_for_papers.rb

@@ -0,0 +1,8 @@
+class ChangeDefaultRatingInCallForPapers < ActiveRecord::Migration
+  def up
+    change_column :call_for_papers, :rating, :integer, :default => 3
+  end
+
+  def down
+  end
+end