ZF-6954: Zend_Soap_Client should accept 'user_agent' http header option


Since it's a functionality of PHP SoapClient, Zend_Soap_Client should accept 'user_agent' option. Becareful that empty string for this option says to SoapClient to not send 'user_agent' header at all, thus Zend_Soap_Client::[get|set]Options() should accept empty string for this option.


fixed in trunk (r19024).

The 'user_agent'-option now accepts empty strings and passes them on to the underlying SoapClient.