~ getLinkID() implemented which extends getLinkMAC() function. In case of virtual network interfaces no appropriate ID was returned. getLinkID() returns a hash of the interface name instead of an empty MAC identifer when no MAC address is available. Further the MAC address is now obtained from the /sys/class/net/* path instead of calling ip command plus expensive grep'ing.
~ getLinkMac() was revised to just return a the MAC address. Additionally it provides a return code for successful retrieval of a MAC address.
~ The ALLOW_DHCPV6_CLIENT call was revised to handle IPv4 protocol too and has been renamed to ALLOW_DHCP_CLIENT accordingly.