Fix a case of 2 invalid oneOf were considered valid

* When using oneOf, one of the schemas should be considered valid for things to be successful.  The old logic would take a schema (that could have had an error) and evaluate against a clean object that could have also contained an error (meaning the logic would assume no error existed)
Update Undefined.php

Fix the php < 5.4 compatability
Update Undefined.php

Doh, missed another php < 5.4 compatibility bug
Merge pull request #95 from gwagner/master

Fix a case of 2 invalid oneOf were considered valid