`rm -rf` for node.
  
  Install with `npm install rimraf`, or just drop rimraf.js somewhere.
  
  ## API
  
  `rimraf(f, callback)`
  
  The callback will be called with an error if there is one.  Certain
  errors are handled for you:
  
  * Windows: `EBUSY` and `ENOTEMPTY` - rimraf will back off a maximum of
    `opts.maxBusyTries` times before giving up.
  * `ENOENT` - If the file doesn't exist, rimraf will return
    successfully, since your desired outcome is already the case.
  
  ## rimraf.sync
  
  It can remove stuff synchronously, too.  But that's not so good.  Use
  the async API.  It's better.
  
  ## CLI
  
  If installed with `npm install rimraf -g` it can be used as a global
  command `rimraf <path>` which is useful for cross platform support.
  
  ## mkdirp
  
  If you need to create a directory recursively, check out
  [mkdirp](https://github.com/substack/node-mkdirp).