start fleshing out some more of the IP socket option optlen cases.
Add the MROUTE socket options
add the MROUTE setsockopt optlens
try some more random optlens for some of the as-yet unannotated protocols
move the IP setsockopt stuff out to its own file
That's pretty much it for ip_setsockopt

All other options will do fine with just the default sizeof(int)
collapse the setsockopt switches into a single switch statement