Removed unnecessary $xml parameter and unwanted brackets.

The parameter `$xml` on the static function toXml is not required as this parameter is being immediately overriden on `line 31`.

The `addAttribute` of method for the variable `$transacType` does not return anything, so it doesn't required to be enclosed with brackets.

Undefined variable `$transactionFile`. Should read `$this->transactionFile` - Issue on `line 285`

Removed duplicate line of code on `Line 316`

Missing initialization of the RuntimeException on `line 84` on Obj2Xml.php