code: private static String determineGlobalRoot() throws IOException {
  		String userhome = System.getProperty("user.home");
  		String whileydir = userhome + File.separator + ".whiley";
  		return whileydir;
  	}
docs: Determine the global root. That is, the hidden whiley directory in the user's
  home directory (e.g. ~/.whiley).
  
  @param tool
  @return
  @throws IOException