added script for running firefox without preexisting instance of x
added script for running firefox without preexisting instance of x

mozilla-services/screenshots,fzzzy/pageshot,fzzzy/pageshot,mozilla-services/screenshots,mozilla-services/pageshot,mozilla-services/screenshots,mozilla-services/screenshots,mozilla-services/pageshot,mozilla-services/pageshot,fzzzy/pageshot,mozilla-services/pageshot,fzzzy/pageshot