Log Message:
Update the NetBSD iSCSI initiator and target to version 20071221.

Changes since previous version:

+ Incorporate a minor build change for platforms without strlcat(3).

+ Add the new "size" keyword to the extent definition when presenting \ 
targets:

When defining extents, the new keyword "size" can be used in the place
of the physical size of the regular file. This is useful for presenting
ISO images to initiators, as in the following:

        In /etc/iscsi/targets:
        # present an ISO image
        extent2         /usr/sets/20071214/release/iso/i386cd.iso 0 size
        target2         ro      extent2         any

        % priv /etc/rc.d/iscsi_target restart
        Stopping iscsi_target.
        Starting iscsi_target.
        Reading configuration from `/etc/iscsi/targets'
        target0:rw:any
                extent0:/tmp/iscsi-target0:0:104857600
        target1:rw:any
                extent1:/tmp/iscsi-target1:0:52428800
        target2:ro:any
                extent2:/usr/sets/20071214/release/iso/i386cd.iso:0:354906112
        DISK: 1 logical unit (204800 blocks, 512 bytes/block), type iscsi fs
        DISK: LUN 0: 100 MB disk storage for "target0"
        DISK: 1 logical unit (102400 blocks, 512 bytes/block), type iscsi fs
        DISK: LUN 0: 50 MB disk storage for "target1"
        DISK: 1 logical unit (693176 blocks, 512 bytes/block), type iscsi fs
        DISK: LUN 0: 338 MB readonly disk storage for "target2"
        TARGET: TargetName is iqn.1994-04.org.netbsd.iscsi-target
        %

Please note that the NetBSD initiator can mount (via vnd) an iSCSI target
presented in this manner. The Microsoft iSCSI initiator sees the read-only
target as a normal SCSI disk, and fails (not surprisingly) to initialize
the disk. It's now possible to make ISO images available via iSCSI, and
NetBSD will DTRT.

In read-only targets, don't attempt to seek to the last block and rewrite
it, it may not work.

Don't assign 8 MB of unused space for use in each iSCSI disk - just use
1MB, which will be enough for the scatter gather iovecs.

Get rid of some dead code.