This fixes an odd error I was seeing in development mode when cache_classes =...

This fixes an odd error I was seeing in development mode when cache_classes = false (the default), specifically when loading an object throught the parent in load_and_authorize_resource.  

Assume Photo model and User model where user has many photos:

@photo = current_user.photos.find(1) # this returns a photo
@photo1 = Photo.find(1)

@photo.kind_of?(Photo) is not always true for some reason when class_cacheing is false.  Where as @photo1.kind_of?(Photo) always appears to be true.  Of interesting note, in the above example @photo != @photo1 if kind_of? is false.  Very odd.
 
Again, this only appears to be when loading and object through an association.

lib/cancan/can_definition.rb

@@ -97,7 +97,7 @@ module CanCan
     end
 
     def matches_subject_class?(subject)
-      @subjects.any? { |sub| sub.kind_of?(Module) && (subject.kind_of?(sub) || subject.kind_of?(Module) && subject.ancestors.include?(sub)) }
+      @subjects.any? { |sub| sub.kind_of?(Module) && (subject.kind_of?(sub) || subject.class.to_s == sub.to_s || subject.kind_of?(Module) && subject.ancestors.include?(sub)) }
     end
 
     def matches_conditions_hash?(subject, conditions = @conditions)