Version 2.6.3

• Fix validations COMPIMPUESTOSC02 and COMPIMPUESTOSC03
  Previously both or any should exists (xnor): nodes Traslado|Retencion and attributes TotalImpuestosTrasladados|TotalImpuestosRetenidos
  Now it allows to have Impuestos totals even when related nodes does not exists
  This is because is not mandatory by Anexo 20
  What is mandatory is that if nodes exists then totals must exists
• Add helper method to create a RequestParameters from a Cfdi
• Fix: add missing dependence ext-iconv into composer.json
• Testing: add helper development script tests/estadosat.php
• Testing: Change CfdiUtils\Validate\Cfdi33\Standard\SelloDigitalCertificado methods visibility compareNames & castNombre for testing