These version allow returning an extension header or other
non–upper-layer protocol if it is the final header before the end of the
packet. This is used to parse the broken packets sent as part of
protocol scan.
This was a mistake that was cauding later IP ID comparisons to be false
because of truncation. In particular, it could make all protocols appear
to be open when doing a -sO scan against localhost because the outgoing
packets looked like protocol replies.
* Adding path-mtu.nse for Path MTU Discovery
* Nmap now stores the MTU for interfaces (from SIOCGIFMTU or libdnet)
* Scripts can access the MTU for host.interface via host.interface_mtu
* Nmap prints the MTU for interfaces in --iflist
