fix tests, implement limits for favorites

app/models/post.rb

@@ -782,7 +782,6 @@ class Post < ActiveRecord::Base
         update_parent_on_destroy
         # decrement_tag_post_counts
         update_column(:parent_id, nil)
-        Post.expire_cache_for_all(tag_array)
         
         unless options[:without_mod_action]
           ModAction.create(:description => "deleted post ##{id}")

app/models/user.rb

@@ -461,15 +461,13 @@ class User < ActiveRecord::Base
     end
     
     def favorite_limit
-      return nil
-      
-      # if is_privileged?
-      #   20_000
-      # elsif is_platinum?
-      #   nil
-      # else
-      #   4_000
-      # end
+      if is_privileged?
+        20_000
+      elsif is_platinum?
+        nil
+      else
+        4_000
+      end
     end
   end