Full switch to clang/ELF. Drop ack. Simplify.

There is important information about booting non-ack images in
docs/UPDATING. ack/aout-format images can't be built any more, and
booting clang/ELF-format ones is a little different. Updating to the
new boot monitor is recommended.

Changes in this commit:

	. drop boot monitor -> allowing dropping ack support
	. facility to copy ELF boot files to /boot so that old boot monitor
	  can still boot fairly easily, see UPDATING
	. no more ack-format libraries -> single-case libraries
	. some cleanup of OBJECT_FMT, COMPILER_TYPE, etc cases
	. drop several ack toolchain commands, but not all support
	  commands (e.g. aal is gone but acksize is not yet).
	. a few libc files moved to netbsd libc dir
	. new /bin/date as minix date used code in libc/
	. test compile fix
	. harmonize includes
	. /usr/lib is no longer special: without ack, /usr/lib plays no
	  kind of special bootstrapping role any more and bootstrapping
	  is done exclusively through packages, so releases depend even
	  less on the state of the machine making them now.
	. rename nbsd_lib* to lib*
	. reduce mtree

tools/mkboot

@@ -76,13 +76,6 @@ bootable | hdboot)
 esac
 
 case $action in
-bootable)
-	# Install the boot monitor on the root device and make it bootable.
-	install -cs -m 644 $mdec/boot $rootdir/boot/boot || exit
-	sync
-	installboot_minix -device $root $mdec/bootblock /boot/boot || exit
-	test $realroot != $root && umount $root
-	;;
 hdboot)
 	# Install a new image on the root device.
 	if [ -e $rootdir/boot/$hdboot_t -a ! -d $rootdir/boot/$hdboot_t ]
@@ -136,14 +129,6 @@ hdboot)
 		mv /boot/minix/.temp /boot/minix/"$target"
 		rm -f /boot/minix_latest
 		ln -s /boot/minix/"$target" /boot/minix_latest 
-
-		# XXX for compatibility with old boot
-		ln -f /boot/minix_latest/kernel /boot/kernel
-		for i in /boot/minix_latest/mod*
-		do
-			lname=`basename $i | sed 's/.*_//'`
-			ln -f "$i" "/boot/$lname"
-		done
 	else
 		# Install the new image.
 		echo "install $hdboot_t $root:/boot/$hdboot_t/$target"
@@ -159,52 +144,6 @@ hdboot)
 	test $realroot != $root && umount $root
 	echo "Done."
 	;;
-fdboot)
-	# fdboot: Make a boot floppy.
-
-	if [ -z "$dev" ]
-	then
-		echo -n \
-"Finish the name of the floppy device to write (by default 'fd0'): /dev/";
-		read dev
-		case "$dev" in
-		'')	dev=/dev/fd0
-			;;
-		/dev/*)
-			;;
-		*)	dev=/dev/$dev
-		esac
-	fi
-
-	# Make a file system.
-	umount $dev 2>/dev/null
-	if mkfs -B 1024 -i 512 $dev
-	then	:
-	else
-		echo "mkfs of $dev failed."
-		exit 1;
-	fi
-
-	# Install /dev, /boot/boot and /boot/image.
-	mount $dev /mnt || exit
-	mkdir -p /mnt/boot/image || exit
-	cpdir /dev /mnt/dev || exit
-	cp -p $mdec/boot /mnt/boot/boot || exit
-	cp -p image /mnt/boot/image/ || exit
-	umount $dev || exit
-
-	# Make bootable and copy the boot parameters.
-	installboot_minix -d $dev $mdec/bootblock /boot/boot || exit
-	pfile=fdbootparams
-	if [ -f $pfile ]
-	then	echo "Using floppy boot parameters from file $pfile."
-		edparams $dev "`cat $pfile`" || exit
-	else	echo "Copying floppy boot parameters from $root."
-		dd if=$root of=$dev skip=1 seek=1 count=1 conv=silent || exit
-	fi
-	edparams $dev 'main(){delay 2000;boot}; save' || exit
-	echo "Test kernel installed on $dev"
-	;;
 esac
 sync
 exit 0