Fixups2

finally I managed to test the v6 code and fixed some issues. neighbor / mass gratious-arp needs to be checked though.

a lot of fancy fixups/usability enhancements/features for DHCPig (short overview)

* more options, fixed v6 supoprt (LL src addr), color output, minimal and debug output
* more options, double the fun: scapy fuzzing, ipv6 support
* more options, more fun: show options/show icmp/show arp
* fixed indentation, beautify doc, eyefriendly one-line-logging