update system tests so validation won't fail when using IANA key

- all tests with "recursion yes" now also specify "dnssec-validation yes",
  and all tests with "recursion no" also specify "dnssec-validation no".
  this must be maintained in all new tests, or else validation will fail
  when we use local root zones for testing.
- clean.sh has been modified where necessary to remove managed-keys.bind
  and viewname.mkeys files.

bin/tests/system/reclimit/clean.sh

@@ -16,3 +16,4 @@ rm -f ns?/named.memstats
 rm -f ns?/named.run
 rm -f ns*/named.conf
 rm -f ns*/named.lock
+rm -f ns*/managed-keys.bind*

bin/tests/system/reclimit/ns1/named.conf.in

@@ -19,6 +19,7 @@ options {
 	listen-on { 10.53.0.1; };
 	listen-on-v6 { none; };
 	recursion no;
+	dnssec-validation no;
 };
 
 zone "." { type master; file "root.db"; };

bin/tests/system/reclimit/ns3/named1.conf.in

@@ -20,6 +20,8 @@ options {
 	listen-on-v6 { none; };
 	servfail-ttl 0;
 	max-recursion-depth 12;
+	recursion yes;
+	dnssec-validation yes;
 };
 
 key rndc_key {

bin/tests/system/reclimit/ns3/named2.conf.in

@@ -20,6 +20,8 @@ options {
 	listen-on-v6 { none; };
 	servfail-ttl 0;
 	max-recursion-depth 5;
+	recursion yes;
+	dnssec-validation yes;
 };
 
 key rndc_key {

bin/tests/system/reclimit/ns3/named3.conf.in

@@ -21,6 +21,8 @@ options {
 	servfail-ttl 0;
 	max-recursion-depth 100;
 	max-recursion-queries 50;
+	recursion yes;
+	dnssec-validation yes;
 };
 
 key rndc_key {

bin/tests/system/reclimit/ns3/named4.conf.in

@@ -21,6 +21,8 @@ options {
 	servfail-ttl 0;
 	max-recursion-depth 100;
 	max-recursion-queries 40;
+	recursion yes;
+	dnssec-validation yes;
 };
 
 key rndc_key {