add a link to the login error message to access API directly

[stevehu]

The login-view is calling the light-oauth2 code service for authentication and authorization. Internally, it uses the Java security GSSAPI to authenticate against the light-portal hybrid-query service. Due to the limitation of the API, there is no way that the error message can be passed to the authentication layer. If authentication is failed, a link will be displayed in the error message. By clicking the link, the hybrid-query loginUser service will be invoked directly, and you can see the error message on the browser.

[stevehu]

add a link to the login error message to access API directly master