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 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

Done cut/paste "word" selection mode support.
It still selects everything which is not space around.

Sponsored by: The FreeBSD Foundation

Sponsored by: The FreeBSD Foundation

wrap long lines.

Sponsored by: The FreeBSD Foundation
Sponsored by: The FreeBSD Foundation

Save last mouse event and check if the button1-up event happen w/o movement,
then ignore it. Otherwise such events broke double/triple click sequence.

Sponsored by: The FreeBSD Foundation

Simplify a bit vtbuf_set_mark.

Sponsored by: The FreeBSD Foundation

Do not add <CR><LF> for last (single) line of paste buffer.

Sponsored by: The FreeBSD Foundation

o Simplify POS_INDEX macro calculation.
o New macro POS_COPY to copy between term_pos_t.
o Add vtbuf_wth/vtbuf_htw helpers, to translate between screen coordinates and
circular history buffer location.
o Update vtbuf_iscursor to mark region selected by mouse.
o New helper vtbuf_flush_mark, to update regions where copy/paste mark changed.
o New method vtbuf_get_marked_len to get storage size for paste buffer.
o vtbuf_extract_marked fill (caller allocated buffer) with selected region data.
o Simplify mouse handler for copy/paste, and use vtbuf_flush_mark to update.
o New method vtbuf_scroll_mode, to help indicate Scroll mode by hiding cursor.
o Update header with new vtbuf methods.
o Add new vt_driver method vd_markedwin, to hold last window with selection.
o Enable paste support in core module.

Sponsored by: The FreeBSD Foundation
Pointed by: Claude Buisson <clbuisson@orange.fr> (Scroll mode indication)

Add mouse related vtbuf operations.

Sponsored by: The FreeBSD Foundation

Fix copyrights.

Sponsored by: The FreeBSD Foundation

o Fix scroll calculations.
o Make vthistory_seek to return amount of lines to update +on_top/-on_bottom of
screen.

Sponsored by: The FreeBSD Foundation

Turn off confusing rotation of scroll history.

Sponsored by: The FreeBSD Foundation

Don't forget to clean terminal window memory. But colors makes more smiles.

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

Readd the vt(4) driver and corresponding tools.