Fixed problem with model and strategy.

The strategy will now return true correctly when it is valid, and the
user has gotten it's authenticate_facebook_user as a class method, not
as an instance method :-)

lib/devise_facebook_open_graph/model.rb

@@ -12,11 +12,10 @@ module ClassMethods
         def facebook_auto_create_account?
           !!facebook_auto_create_account
         end
-      end
-
 
-      def authenticate_facebook_user(facebook_uid)
-        self.class.send "find_by_" + facebook_uid_field, facebook_uid
+        def authenticate_facebook_user(facebook_uid)
+          self.class.send "find_by_" + facebook_uid_field, facebook_uid
+        end
       end
     end
   end

lib/devise_facebook_open_graph/strategy.rb

@@ -11,7 +11,7 @@ class FacebookOpenGraphAuthenticatable < ::Devise::Strategies::Base
         # current application's domain cookies.
         #
         def valid?
-          mapping.respond_to?(:authenticate_facebook_user) && cookies.has_key?(::DeviseFacebookOpenGraph::Facebook::Config.facebook_session_name)
+          mapping.to.respond_to?(:authenticate_facebook_user) && cookies.has_key?(::DeviseFacebookOpenGraph::Facebook::Config.facebook_session_name)
         end
 
         def authenticate!