code: private String resolveDocByPackage(String className) {
          int index = className.lastIndexOf(".");
          String packageName = className;
          while(index > 0) {
              packageName = packageName.substring(0, index);
              String urlBase = doc.getProperty(packageName);
              if(urlBase != null) {
                  return urlBase + className.replace(".", "/")+".html";
              }
              index = packageName.lastIndexOf(".");
          }
          return null;
      }
docs: Return JavaDoc URL for package. Check package names recursively per dot, starting
  with the most specific package.
  
  @param className Package Name to find JavaDoc for.
  
  @return JavaDoc URL for package