Switch default console tty from /dev/console to /dev/constty

With this switch processes (such as xconsole) can open /dev/console
without breaking login on the text or serial console. This can be
trivially triggered by enabling xdm in rc.conf and hitting
Ctrl+Alt+F1 or equivalent once booted.

The changes:
- Add entry for /dev/console or /dev/constty if missing
- If a port's had /dev/console 'on' switch it off and enable /dev/constty
- If a port did not have /dev/console 'on', leave /dev/constty off

Some ports had /dev/console off and /dev/ttyE0 enabled, presumably to
avoid just this issue. It may make sense to adjust these also (but not
in this pass)

As discussed on current-users

add ttyC00/ttyC01 as found on eg, com(4)-based serial port systems like
the sunblade 2500.

Change the default console from wsemul_sun/sun-ss5 to wsemul_vt100/wsvt25.
This allows for a colour console, fixes home/end keys not working and
works with the embedded wsvt25 description in libterminfo.

Add a constty entry, marked 'off', with otherwise the same settings
as the console. Now when coming up in single user mode the tset in
/.profile can set the terminal type correctly.
Note: I believe constty should be 'on' and console 'off', but thats a
separate discussion

branches: 1.8.20;
Add wscons virtual consoles

branches: 1.7.2;
remove ad-hok list of pty's from port tty files, and auto-generate it so
that it is consistent, and in the proper order.

Revert 'console' back to /dev/console (from /dev/constty)

Change 'console' login to use /dev/constty so that its output isn't
stolen by code that requests system messages using TIOCCONS.

Add ttyh[01] for sab.

Added ttyp[g-zA-Z] (bin/15594).

This should be the final part of moving to 64 PTYs by default. Added
entries for tty{r,s}{0,1,2,3,4,5,6,7,8,9,a,b,c,d,e,f} to /etc/ttys.

Thanks to Matthew Green for pointing out the need.

branches: 1.1.10;
My own special /etc.

add ttyC00/ttyC01 as found on eg, com(4)-based serial port systems like
the sunblade 2500.

Change the default console from wsemul_sun/sun-ss5 to wsemul_vt100/wsvt25.
This allows for a colour console, fixes home/end keys not working and
works with the embedded wsvt25 description in libterminfo.

Add a constty entry, marked 'off', with otherwise the same settings
as the console. Now when coming up in single user mode the tset in
/.profile can set the terminal type correctly.
Note: I believe constty should be 'on' and console 'off', but thats a
separate discussion

branches: 1.8.20;
Add wscons virtual consoles

branches: 1.7.2;
remove ad-hok list of pty's from port tty files, and auto-generate it so
that it is consistent, and in the proper order.

Revert 'console' back to /dev/console (from /dev/constty)

Change 'console' login to use /dev/constty so that its output isn't
stolen by code that requests system messages using TIOCCONS.

Add ttyh[01] for sab.

Added ttyp[g-zA-Z] (bin/15594).

This should be the final part of moving to 64 PTYs by default. Added
entries for tty{r,s}{0,1,2,3,4,5,6,7,8,9,a,b,c,d,e,f} to /etc/ttys.

Thanks to Matthew Green for pointing out the need.

branches: 1.1.10;
My own special /etc.

This should be the last piece of the move to 64 default PTYs. /etc/ttys now
has entries for 64 ptys.

Thanks to Matthew Green for pointing out the need for this.

Pull up revision 1.8 (requested by martin in ticket #384):
Add wscons virtual consoles

Sync with HEAD.