Fix Validator::validate_match Bug

The `Validator::validate_match` method currently chokes on any Regular Expression containing a comma. For example: `/^\d{2,4}$/`

The fix updates `Validator::parse` to check the `$rule` name. If `$rule` is "match", the regular expression is extracted, and placed straight into the `$parameters` array. Everything else is passed to the `str_getcsv` method, as before.

Stephen