message: abspath is actually what the basePath option of Bundler class is.  Just wiring it up.
diff: @@ -186,6 +186,7 @@ function stringToRegExp(str: string) {
  return new RegExp(str.replace(/[-\/\\*+?.()|[\]{}]/g, '\\$&'));
  }
  +options.basePath = options['abspath'];
  options.excludes = options.exclude || [];
  options.redirects = options.redirect || [];
  options.stripExcludes = options['strip-exclude'] || [];
  