The blist_meta_* routines that process a subtree take arguments 'radix' and
'skip', which denote, respectively, the largest number of blocks that can be
managed by a subtree of that height, and one less than the number of nodes
in a subtree of that height. This change removes the 'skip' argument from
those functions because 'skip' can be trivially computed from 'radius'.
This change also redefines 'skip' so that it denotes the number of nodes in
the subtree, and so changes loop upper bound tests from '<= skip' to '<
skip' to account for the change.

The 'skip' field is also removed from the blist struct.

The self-test program is changed so that the print command includes the
cursor value in the output.

Submitted by: Doug Moore <dougm@rice.edu>
MFC after: 1 week