analyzeCss: make it work on Windows
analyzeCss: make it work on Windows

* detect Windows environment and run cmd shim instead of a symlink

william-p/phantomas,ingoclaro/phantomas,gmetais/phantomas,william-p/phantomas,gmetais/phantomas,macbre/phantomas,ingoclaro/phantomas,macbre/phantomas,ingoclaro/phantomas,gmetais/phantomas,macbre/phantomas,william-p/phantomas