Recent work on the gnu cpio seems to have introduced some bugs, it

Recent work on the gnu cpio seems to have introduced some bugs, it
complains about "Malformed numbers" while unpacking the dists and
what winds up on the disk isn't correct.  Use this as an opportunity
to switch over to bsdcpio since at this point we don't even build
and install the gnu cpio by default.  Note sysinstall needed to be
tweaked a bit (dropping tape block size setting) because it seems
bsdcpio doesn't do anything with block sizes, at least as far as
reading from archives goes.  That wasn't really a problem since
installations from tape have been broken for a while and the rest
of sysinstall's tape support code will be removed shortly.