ipfw -- interface for firewall, packet scheduler, NAT and so on.
It is comprised of several components: the kernel firewall filter rule processor and its integrated packet accounting facility, the logging facility, NAT, a forward facility, a bridge facility, and an ipstealth facility.
Note that the `dummynet` traffic shaper is not merged.
Changes:
Remove directory `ipc`, and add a new directory `compat`.
Directory `compat` includes some FreeBSD source files to be compatible
with Linux.
Port FreeBSD ifconfig to F-Stack.