Don't malloc a buffer while holding the prison0 mutex.  Instead, use a loop
where we figure out the hostname length under the lock, malloc the buffer
with the lock dropped, then recheck the length under the lock and loop again
if the buffer is now too small.

Approved by:	re (kib)

- Add more mappings for Greek characters and the Euro sign.
- Print UTF-8 characters in the log file as hexadecimal.

Characters between 0x07 and 0x0d are now also mapped, which means we can
display almost 256 different characters. Also remap certain types of
dashes and quotes, which means we can finally read our manual pages
without red question marks in them.

Submitted by:	Christoph Mallon

parameters they represent, and the variables they replaced, instead of
abbreviated versions of them.

Approved by:	bz (mentor)

Add a small Unicode-to-CP437 remapping table to at least demonstrate
that the terminal emulator is perfectly capable of handling UTF-8. This
will of course break if the user loads a different font map, but it at
least allows people to give it a try.

I can now see the box drawing in dialog(1) and the arrows in mutt(1)
correctly.

Because we only support a single argument to tf_param, use 16 bits for
the pitch and 16 bits for the duration. While there, make the argument
unsigned. There isn't a single param call that needs a signed integer.

Submitted by:	danfe (modified)

The system hostname is now stored in prison0, and the global variable
"hostname" has been removed, as has the hostname_mtx mutex.  Jails may
have their own host information, or they may inherit it from the
parent/system.  The proper way to read the hostname is via
getcredhostname(), which will copy either the hostname associated with
the passed cred, or the system hostname if you pass NULL.  The system
hostname can still be accessed directly (and without locking) at
prison0.pr_host, but that should be avoided where possible.

The "similar information" referred to is domainname, hostid, and
hostuuid, which have also become prison parameters and had their
associated global variables removed.

Approved by:	bz (mentor)

I don't want people to override the mutex when allocating a TTY. It has
to be there, to keep drivers like syscons happy. So I'm creating a
tty_alloc_mutex() which can be used in those cases. tty_alloc_mutex()
should eventually be removed.

The advantage of this approach, is that we can just remove a function,
without breaking the regular API in the future.

Apart from the 16 virtual terminals, Syscons allocates two device nodes
that should not really be TTYs, even though they are. One of them is
consolectl. In RELENG_7 and before, these device nodes are used in
single user mode. After I simplified input path, we only use this device
node to call ioctl() on (moused, Xorg, vidcontrol).

When you call ioctl() on consolectl, it will behave the same as being
called on the first window.