this haven't caused a real bug, I just noticed it while tracing.
it may be dangerous if in some flow, the stack will not be zeroed

Instead of a subclass, make it a thread attribute.  This simplifies usage
and also allows detaching a thread after creation.

read_random() is used indirectly by the TCP stack to randomize a local port number,
before this patch it was identical in each execution, and that caused NAT problems.

also add a FIXME note to implement real random one day.

the linux/musl definition is 2 bytes long instead of 1 byte as in
freebsd, this patch is fixing this issue which caused ifconfig to fail

Attempting to put an end to the linux<->freebsd confusion.

We already get most of this from <sys/param.h>

Add includes where needed, remove duplicate definitions

This isn't actually a BSD native API as FreeBSD uses a per-cpu variable
to store cpuids, but rather a replacement we can use.

will be used to set the default gateway or set a network route
for example by doing:

route add -net x.x.x.x netmask x.x.x.x gw x.x.x.x

SIOCSIFFLAGS should be sent in anyway in order to initialize the interface,
the SIOCGIFFLAGS returned IFF_UP for some reason so it should be further
investigated, add a fixme for now

the lack of extern "C").

This is a way to sleep without a wakeup channel.

I had to rename the symbol to bsd_pause because it conflicts with the classic
Unix pause syscall exposed through unistd.h via libcstd++.

NET_RT_IFLIST (list interfaces) and NET_RT_DUMP (dump rout entries).

This flag implies the created thread is not started, but we currently
always start it. In addition the thread_lock/sched_add/thread_unlock
mess the BSD code usually does is something we'd rather avoid for now.

Linux IOCTL commands in addition to the BSD IOCTLS. Linux IOCTLs should be
used instead of BSD IOCTLs whenever possible.

Added support for passing bsd commands to setsockopt() by negating the bsd cmd values. This is guarnteed NOT to clash with Linux commands.