various updates to build with xorg-server 21.1.3.

- the s3, tga, and trident drivers use old functionality and are disabled
- dixmods/fb is removed, main fb has all these now (we retain our revert
of an upstream change here.)
- adjust source lists as necessary
- remove vbe module, now part of int10
- use -lxcvt
- misc clean up
- ramdac loses IBM, BT and TI support (this is one of the problems for
the disabled drivers, but also some structures in RamDac.h are gone
entirely, not copied anywhere.)
- old apm code is gone, all bsd uses pm_noop. now

this probably require a clean build in at least xorg-server and the
drivers, and perhaps the DESTDIR as well. will update src/UPDATING with
details when they are fully known.

xorg-server: Enable wscons-based autoconfiguration.

This gets us features like automatic configuration of touchscreens,
and X's default keyboard layout matching the console's.

first merge of xorg-server 1.18.4 reach over. not tested, and
missing at these new subdirs, some which may not be needed:

dri2
glamor
hw/xfree86/drivers/modesetting
hw/xfree86/parser
present
pseudoramiX

branches: 1.1.2; 1.1.6;
add xorg-server build support for composite, config and exa.

xorg-server: Enable wscons-based autoconfiguration.

This gets us features like automatic configuration of touchscreens,
and X's default keyboard layout matching the console's.

first merge of xorg-server 1.18.4 reach over. not tested, and
missing at these new subdirs, some which may not be needed:

dri2
glamor
hw/xfree86/drivers/modesetting
hw/xfree86/parser
present
pseudoramiX

branches: 1.1.2; 1.1.6;
add xorg-server build support for composite, config and exa.

first merge of xorg-server 1.18.4 reach over. not tested, and
missing at these new subdirs, some which may not be needed:

dri2
glamor
hw/xfree86/drivers/modesetting
hw/xfree86/parser
present
pseudoramiX

branches: 1.1.2; 1.1.6;
add xorg-server build support for composite, config and exa.