Fix to support LLVM/ruby that ships with Xcode 5.1
Merge pull request #577 from seanknox/fix-xcode51-ruby

Fix to support LLVM/ruby that ships with Xcode 5.1
Merge branch 'master' of https://github.com/boxen/our-boxen
Includes fix for Xcode 5.1 to fix the "ARCHFLAGS=-Wno-error=unused-command-line-argument-hard-error-in-future ./script/boxen" bandaid during setup of boxer on a new client.