rtl8168-mac-eeprom utility

Usage:

	./rtl8168_mac_eeprom
will generate an EEPROM backup file for all supported cards

	./rtl8168_mac_eeprom -s 1:0
will generate an EEPROM backup file for PCI slot 1:0

	./rtl8168_mac_eeprom -s 1:0 -m 01:02:03:04:05:06
will set the new mac address 01:02:03:04:05:06 to PCI slot 1:0
