ProcessEnvironments now run in a clean shell

Swift Script processEnvironments now runs in a clean shell with OS X Swift SDK, as under certain conditions it caused project to fail to build (Unsupported Architecture #7).
Fix for spaces in header path

If header path has spaces in it, this script fails at line: 33.
Additional fix for spaces in paths

Updated the script to work with spaces in paths
Merge pull request #8 from Legoless/master

ProcessEnvironments now run in a clean shell