Renamed package, split error decoration from handling

Same for the grant token error with wrong password:
curl -u "5944357967603171000:llPL9N5Du7HmG5JHdgbTrV" --data "grant_type=password&username=userxin&password=bar1" -i http://127.0.0.1:8081/oauth/token
HTTP/1.1 403 Forbidden
X-Powered-By: Express
Vary: Origin, Accept-Encoding
Access-Control-Allow-Credentials: true
Content-Type: application/json
Date: Mon, 22 Dec 2014 15:46:15 GMT
Connection: keep-alive
Transfer-Encoding: chunked

{"error":"invalid_grant","error_description":"Invalid resource owner credentials"}