Add --service_json_path flag to support mixologist
Add --service_json_path flag to support mixologist

1. service_json_path flag is hidden
2. --fetch / no-fetch hidden options are removed
  if service_json_path is specifier, it implies
  no-fetch

Change-Id: I52e9e190dfdbe50949cb4e1970245b8ed6b9523e

cloudendpoints/esp,cloudendpoints/esp,cloudendpoints/esp,cloudendpoints/esp,cloudendpoints/esp,cloudendpoints/esp,cloudendpoints/esp,cloudendpoints/esp