[SoapClient] Added ability to add cURL options later

[timonf]

It's very hard to implement those cURL constants and options into the existing client.builder service. It would be much easier to inject parameters later.

// example code
$this->client = $builder->build(); // $builder from DIC "besimple.soap.client.builder"
$this->client->setRequestOption(CURLOPT_SSL_VERIFYHOST, 0);
$this->client->setRequestOption(CURLOPT_SSL_VERIFYPEER, 0);
$response = $this->client->__soapCall($functionName, $arguments);

So I've added setRequestOption method to SoapClient.

[delatbabel]

LGTM. I need to set the CURL options: CURLOPT_SSL_VERIFYPEER, CURLOPT_SSLCERT, CURLOPT_SSLKEY, and a few others. It appears to me that it's impossible to use the BeSimple SOAP client if I need to set any non-standard SOAP options without this PR being merged.