Fixes a silent memory error during splat drawing when splats cross the
bottom of the screen.

Add check netgame check if someone use both -noipv4 and -noipv6

Do not error out if we don't have a socket for an address family we have disabled

fixup

Add checks for return code for ioctl(), setsockopt(), getsockopt() and getsockname()
Also show errno and strerror for failed calls