code: public static DownloadProperties wgetGithub(final String branch, final File destination) {
      return new DownloadProperties(new WgetGithubDownloader(branch), destination);
    }
docs: Builds a new DownloadProperties for downloading Galaxy from github using wget.
  @param branch The branch to download (e.g. master, dev, release_15.03).
  @param destination The destination directory to store Galaxy, null if a directory
  should be chosen by default.
  @return  A DownloadProperties for downloading Galaxy from github using wget.