mod_http_oauth2: Handle login_hint without @hostpart Makes life easier for the client when it does not know the full JID, which might not have the same hostpart as the authorization server URL.

2c07bcf56a36d6e74dc0f5422e89bd61f4d31239 0.8-diverge
1656d4fd71d07aa3a52da89d4daf7723a555e7dd last-google-code-commit