Also, I've heard a number of good things about Grunt, but I'm wondering why you chose to use it over adding another Makefile target that concatenates like we already do. AFAIK, we can't switch over the entire Makefile to grunt due to us needing `-j4` to make running tests tractable and access to Unix command-line tools (the latter of which we could potentially remove if we rewrote the sed line using CoffeeScript).