Correctly handle catalog zone entries containing slashes

- Add quotes before and after zone name when generating "addzone"
  input so avoid "unexpected token" errors.
- Use a hex digest for zone filenames when the zone or view name
  contains a slash.
- Test with a domain name containing a slash.
- Incidentally added 'catzhash.py' to contrib/scripts to generate
  hash labels for catalog zones, as it was needed to write the test.

contrib/scripts/catzhash.py

@@ -0,0 +1,30 @@
+#!/usr/bin/python
+# Copyright (C) Internet Systems Consortium, Inc. ("ISC")
+#
+# This Source Code Form is subject to the terms of the Mozilla Public
+# License, v. 2.0. If a copy of the MPL was not distributed with this
+# file, You can obtain one at http://mozilla.org/MPL/2.0/.
+#
+# See the COPYRIGHT file distributed with this work for additional
+# information regarding copyright ownership.
+
+# catzhash.py: generate the SHA-1 hash of a domain name in wire format.
+#
+# This can be used to determine the label to use in a catalog zone to
+# represent the specified zone. For example, the zone
+# "domain.example" can be represented in a catalog zone called
+# "catalog.example" by adding the following record:
+#
+# 5960775ba382e7a4e09263fc06e7c00569b6a05c.zones.catalog.example. IN PTR domain.example.
+#
+# The label "5960775ba382e7a4e09263fc06e7c00569b6a05c" is the output of
+# this script when run with the argument "domain.example".
+
+import sys
+import dns.name
+import hashlib
+
+if len(sys.argv) < 2:
+    print("Usage: %s name" % sys.argv[0])
+
+print (hashlib.sha1(dns.name.from_text(sys.argv[1]).to_wire()).hexdigest())