Idea: automatically pick up the name of the package script

[rauschma]

cross-os could automatically pick up the name of the package script (via process.env.npm_lifecycle_event):

{
  "scripts": {
    "user": "cross-os" // no argument!
  },
  "cross-os": {
    "user": {
      "darwin": "echo $USER",
      "win32": "echo %USERNAME%",
      "linux": "echo $USER"
    }
  },
  ···
}