[R6RS] Implicit naming for record procedures

[dyb at cs.indiana.edu]

> The point of implicit naming isn't just "grep"---it's also that
> all-too-often the names that I want aren't the ones implicit naming
> would choose.

This also happens to me sometimes.  Chez Scheme's define-record permits
you to override the constructor name, predicate name, and setter/accessor
prefix.  But I would go along with one that allowed you to get even
more specific about accessor and setter names.  It's rare, however,
that I want to override all of the names, so please let's not force it
to be all explicit or all implicit.

Kent