Added EtTriggeredSend::EtClientId property in order to generate valid SO...

My SOAP calls need subaccount client ID, because of my company account profile;

https://help.exacttarget.com/fr-FR/technical_library/web_service_guide/technical_articles/reviewing_soap_envelopes_to_retrieve_information/

NOTE: The SOAP envelopes include a client ID value that can be used to perform calls in sub-accounts, such as in an Enterprise 2.0 account. If you are performing the action in the same account you are logged into, you do not need to include this value.


	<SOAP-ENV:Body>
		<ns1:CreateRequest>
			<ns1:Options/>
			<ns1:Objects xsi:type="ns1:TriggeredSend">
				<ns1:Client>
					<ns1:ID>7001292</ns1:ID>
				</ns1:Client>

In order to generate a correct XML in EtSoapClient, I needed to add this property inside EtTriggeredSend:

    public $Client; // EtClientID

This wont collide with protected $client (PHP class attributes are case-sensitive).