Fiscal Printers directives

Some countries require fiscal printers, or non-resettable grand-total values to be kept for each POS.

NRGT directives

Directive	Description
</NRGT_CC>	todo
</NRGT_CC2>	todo
</NRGT_UNITID>	todo
</TAX_AUTH_LOGO>	todo
</TAX_AUTH_STRING>	todo