Fix for client_id in req parm and auth header

pull request - replaces https://github.com/spring-projects/spring-security-oauth/pull/90.

Fix problem of client_id being sent in basic authorization header and request parameter. See: http://forum.springsource.org/showthread.php?141347-client_id-passed-as-request-parameter-and-in-http-basic-authorization

I didn't notice any errors when i ran the integration-test target.  Let me know if you have problems. 

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