support for addzone/delzone feature (see change
#2930). Removed "new-zone-file" option, replaced
with "allow-new-zones (yes|no)". The new-zone-file
for each view is now created automatically, with
a filename generated from a hash of the view name.
It is no longer necessary to "include" the
new-zone-file in named.conf; this happens
automatically. Zones that were not added via
"rndc addzone" can no longer be removed with
"rndc delzone". [RT #19447]
