Description:
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When trying to make a request with the PUT or DELETE action the extra parameters sent in the body are not being included on the signature process on the server.

Test script:
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$oauth = new OAuth("9538568fb3756eeff20e71c0e9b62f7cd11b2656","34aa6f4f51d53212b34df53c316645bd2cab4edf",OAUTH_SIG_METHOD_HMACSHA1,OAUTH_AUTH_TYPE_AUTHORIZATION);

	$x = array(1,2,3 => array(1,2,3 => array(1,2,3)));

	$data = array('data' => json_encode($x)); 

	$oauth->fetch("http://api.alex.espressonew.com/index/index",$data,OAUTH_HTTP_METHOD_PUT);

Expected result:
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The signature should be valid

Actual result:
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The server response 

oauth_problem=signature_invalid&debug_sbs=PUT&http%3A%2F%2Fapi.alex.espressonew.com%2Findex%2Findex&oauth_consumer_key%3D9538568fb3756eeff20e71c0e9b62f7cd11b2656%26oauth_nonce%3D100529351351adf305966404.17335333%26oauth_signature_method%3DHMAC-SHA1%26oauth_timestamp%3D1370354437%26oauth_version%3D1.0

The debug info from the client

PUT&http%3A%2F%2Fapi.alex.espressonew.com%2Findex%2Findex&data%3D%257B%25220%2522%253A1%252C%25221%2522%253A2%252C%25223%2522%253A%257B%25220%2522%253A1%252C%25221%2522%253A2%252C%25223%2522%253A%255B1%252C2%252C3%255D%257D%257D%26oauth_consumer_key%3D9538568fb3756eeff20e71c0e9b62f7cd11b2656%26oauth_nonce%3D100529351351adf305966404.17335333%26oauth_signature_method%3DHMAC-SHA1%26oauth_timestamp%3D1370354437%26oauth_version%3D1.0