Try to extract the RFC1048 data from PXE. If we get enough info we can skip the bootp().
It removes unnecessary DHCP request from pxeloader.
I'm not sure if it should be a default, maybe somebody wants to give a different answer from DHCP, depends on stage of netboot on the same machine.
Initiated by: Matthew Dillon
Improved by: oshogbo
Sponsored by: Oktawave