mojombo/jekyll — pull request #1571 by parkr (2013-09-22 22:27:22+00:00)
Title: Use + instead of Array#concat

[Don't use destructive Array#concat for Liquid Attribute arrays](https://github.com/mojombo/jekyll/commit/26dc14881c444198f2c57d740d8ab126525a5b67#commitcomment-4150434)