move mesa10 build into .old scheme:

- add ${X11SRCDIR.MesaLib.old} and introduce ${X11SRCDIR.Mesa} as an
alias for either the former or the non old. this allows many of
the makefiles to simply use ${X11SRCDIR.Mesa} (but does not really
enable much sharing of makefiles, but reduces their diffs.)

- use mesa-which.mk to define ${OLD_PREFIX} to either "" or ".old",
and to know if to build 'dri7' (.old only.) ${OLD_PREFIX} is used
by other code (eg, LIBDPLIBS) to pick the right subdir.

round do of reach over updates for xorg-server 1.18. again, untested,
but this should be much closer to complete for the necessary changes.

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

no longer build a bunch of xorg-server twice (for .a and _pic.a).
entirely obsolete installing libi2c since it's builtin.

libfb, libdri and libdri2 all want to be both .a for the Xorg link
and .so for the run-time, i didn't really look too closely.

remove a bunch of duplicated set list entries.

i built a bunch of platforms for this, and i think i got the sets
lists updates correct, including for debug sets, but it's probable
that i broke something.

XXX: pullup to netbsd-7, but not critical

many build updates and fixes for xorg-server 1.9.2.

updates for changed header locations for libdrm.

XXX: use -Wno-error for files that use old foostr.h includes that now have
XXX: #warning's in them.

Move libdrm headers up one level (out of the X11 directory) to match
the rest of the world and fix the inconsistency with libdrm.pc.
Fixes PR xsrc/42126.

build updates for xorg-server 1.6.

upgrade the build framework for xorg-server 1.6.

this doesn't quite work yet. Xvfb and Xnest attempt to link but
have missing symbols. Xorg doesn't build all its components yet.

branches: 1.4.2; 1.4.6; 1.4.8; 1.4.14;
use XORG_VERSION_CURRENT defined in Makefile.serverlib instead of
defining it all over the shop

stop using XSERVERINCDIR since it was referencing src/x11 reachover
this is not correct for xorg reachover

* install libdri.so to modules/extensions
* libdri.so depends on libdrm

add dri, int10 & loader subdirs to hw/xfree86.

round do of reach over updates for xorg-server 1.18. again, untested,
but this should be much closer to complete for the necessary changes.

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

no longer build a bunch of xorg-server twice (for .a and _pic.a).
entirely obsolete installing libi2c since it's builtin.

libfb, libdri and libdri2 all want to be both .a for the Xorg link
and .so for the run-time, i didn't really look too closely.

remove a bunch of duplicated set list entries.

i built a bunch of platforms for this, and i think i got the sets
lists updates correct, including for debug sets, but it's probable
that i broke something.

XXX: pullup to netbsd-7, but not critical

many build updates and fixes for xorg-server 1.9.2.

updates for changed header locations for libdrm.

XXX: use -Wno-error for files that use old foostr.h includes that now have
XXX: #warning's in them.

Move libdrm headers up one level (out of the X11 directory) to match
the rest of the world and fix the inconsistency with libdrm.pc.
Fixes PR xsrc/42126.

build updates for xorg-server 1.6.

upgrade the build framework for xorg-server 1.6.

this doesn't quite work yet. Xvfb and Xnest attempt to link but
have missing symbols. Xorg doesn't build all its components yet.

branches: 1.4.2; 1.4.6; 1.4.8; 1.4.14;
use XORG_VERSION_CURRENT defined in Makefile.serverlib instead of
defining it all over the shop

stop using XSERVERINCDIR since it was referencing src/x11 reachover
this is not correct for xorg reachover

* install libdri.so to modules/extensions
* libdri.so depends on libdrm

add dri, int10 & loader subdirs to hw/xfree86.