Copy stable/9 to releng/9.3 as part of the 9.3-RELEASE cycle.

Approved by: re (implicit)
Sponsored by: The FreeBSD Foundation

MFC r263885

o Add new vd_driver method to do bitblt with mask, named vd_maskbitbltchr.
o Move vd_bitbltchr vga's driver method to vd_maskbitbltchr.
o Implement new vd_bitbltchr method for vga driver. (It do single write for 8
pixels, have to be a bit faster).

Sponsored by: The FreeBSD Foundation

MFC 219886, 226100, 226111, 226341, 242529, 259015, 259016, 259019, 259049,
259071, 259102, 259110, 259129, 259130, 259178, 259179, 259203, 259221,
259261, 259532, 259615, 259650, 259651, 259667, 259680, 259727, 259761,
259772, 259776, 259777, 259830, 259882, 259915, 260160, 260449, 260450,
260688, 260888, 260953, 261269, 261547, 261551, 261552, 261553, 261585
o Merge vt(4) virtual terminal (a.k.a. newcons) to stable/9.
o Merge teken updates.
o Add few more tty methods required by vt(4).
o Update syscons(4) to work with fresh teken.

Sponsored by: The FreeBSD Foundation

Merge VT(9) project (a.k.a. newcons).

Reviewed by: nwhitehorn
MFC_to_10_after: re approval

Sponsored by: The FreeBSD Foundation

Update vd_bitbltchr_t type to handle operation mask (to not touch pixels which
is not defined in mask) and bpl (bytes per source line).
Only vt_fb driver handle handle bpl yet.
Add protector for case when blitting image can be drawn partially out of screen,
like mouse cursor.

Mouse cursor and its movements works fine, copy/paste not yet.

Sponsored by: The FreeBSD Foundation

o Rename bitblt method to bitbltchr, since it used to copy char with bg/fg colors
from font table, but not bitmap copy.
o Fix small mistake in comment.

Sponsored by: The FreeBSD Foundation

o Implement history buffer.
o Join history buffer with screen buffer. Same type of things.
o Reimplement buffer as an array of rows. Make it circular, so no overflow
tracking.
o Implement VT_PROCESS mode. Locking of VT switching by owner process.
o Add debug and deadtimer sysctls. deadtimer - defaulting to 15 seconds, time
to wait process answer in VT_PROCESS mode, to do VT switch in case when
process hang.
o Implement later console attach.
o Fix (partially yet) keyboard allocation.
o Add drivers priority. Disallow to replace KMS driver with VGA.
o Add ability to resize terminals.

Sponsored by: The FreeBSD Foundation

Add support fot ia64. This means that ia64, for the first time ever,
has a working non-serial console!

I'm pretty sure this doesn't work on the SGI Altix 350, but that's
ok for now. Lot's of things don't work there...

Chase KPI change in vga driver.

Readd the vt(4) driver and corresponding tools.