Log Message:
Update to version 20070615 of the NetBSD iSCSI target:

Add IPv6 to target and test harness
Add -4 and -6 args to the iscsi-target and the test harness
Fix some debugging information
Fix bug in InitialR2T desired transfer length calculation (from yamt)
Fix bug in netmask calculation
Get rid of some magic constants
Add VPD 80 handling
Add RESERVE6 and RELEASE6 to target (Persistent Reservations In
        partially supported - read keys, and report capabilities)
Use poll in preference to select, if we have it