Brings possibility to upgrade to other profile via secret parameter...

Brings possibility to upgrade to other profile via secret parameter FACTURX_PROFILE. If this is set to 10 (Profile PROFILE_XRECHNUNG_3) and the other added parts, this makes it possible to update to newer version which is supported in germany. With this is was possible to generate an invoice which is completely valid against an government check: https://erechnungsvalidator.service-bw.de/

Future version could make the secret parameter moved to admin board to select the profile via dropdown.