TechEmpower/FrameworkBenchmarks — pull request #929 by hamiltont (2014-07-16 19:22:50+00:00)
Title: Preserve TFB_ variables when replacing environment

I broke the environment variables when we merged #915 with [this line](https://github.com/TechEmpower/FrameworkBenchmarks/pull/915/files#diff-f92ef1689e8d44a3ba6ded6ba5ee3853R34). This fixes that by ensuring that replace_environ
preserves any variables that start with TFB