add space in multiword model in I18n unauthorized message - closes #292

spec/cancan/ability_spec.rb

@@ -395,6 +395,7 @@ describe CanCan::Ability do
     it "should have variables for action and subject" do
       I18n.backend.store_translations :en, :unauthorized => {:manage => {:all => "%{action} %{subject}"}} # old syntax for now in case testing with old I18n
       @ability.unauthorized_message(:update, Array).should == "update array"
+      @ability.unauthorized_message(:update, ArgumentError).should == "update argument error"
       @ability.unauthorized_message(:edit, 1..3).should == "edit range"
     end
   end