Fix pattern for classes extending SoapClient.

The current pattern has two problems:
- It does not match \SoapClient
- It matches any non-word characters after SoapClient. Thus line breaks and the beginning of docblocks are included and replaced.
Adds test for overwriting SoapClient when extending from the base class \SoapClient.
Adds VCR's SoaplClient to blacklist.
Merge pull request #31 from php-vcr/fix-soap-extend-replacement

Fix soap extend replacement