the built-in trust anchors in named and delv are sufficent for
validation. named still needs to be able to load trust anchors from
a bind.keys file for testing purposes, but it doesn't need to be
the default behavior.
we now only load trust anchors from a file if explicitly specified
via the "bindkeys-file" option in named or the "-a" command line
argument to delv. documentation has been cleaned up to remove references
to /etc/bind.keys.
Closes#3850.
9bb46262af