1.0.9.43: .PV-CELL., use .PV. directly

1.0.9.43: .PV-CELL., use .PV. directly

* Now that .CALLS. are gone we can get rid of the extra indirection.
  (Maybe we have to add it back later, but worry about that then.)

* Since .PV. is magical, also localize its bindings to vector.lisp,
  instead of exposing the variable in PV-BINDING1's interface (which
  is used elsewhere as well.)