basic (WARNING: Overwrites your .gitignore file)
curl -sS https://raw.github.com/daxxog/gitignore-cloud9/master/.gitignore > .gitignore
or safe install with gitignoree.js
npm install https://github.com/daxxog/gitignoree.js/tarball/master
curl https://raw.github.com/daxxog/gitignore-cloud9/master/.gitignore | gitignoree