perform a more complete cleanup after running system tests [rt41255]

(cherry picked from commit ecfedec0e0)

Conflicts:
	bin/tests/system/acl/clean.sh
	bin/tests/system/addzone/clean.sh
	bin/tests/system/allow_query/clean.sh
	bin/tests/system/autosign/clean.sh
	bin/tests/system/case/clean.sh
	bin/tests/system/checknames/clean.sh
	bin/tests/system/dlzexternal/clean.sh
	bin/tests/system/dscp/clean.sh
	bin/tests/system/ednscompliance/clean.sh
	bin/tests/system/emptyzones/clean.sh
	bin/tests/system/formerr/clean.sh
	bin/tests/system/forward/clean.sh
	bin/tests/system/glue/clean.sh
	bin/tests/system/limits/clean.sh
	bin/tests/system/lwresd/clean.sh
	bin/tests/system/masterfile/clean.sh
	bin/tests/system/names/clean.sh
	bin/tests/system/nslookup/clean.sh
	bin/tests/system/nsupdate/clean.sh
	bin/tests/system/sfcache/clean.sh
	bin/tests/system/sit/clean.sh
	bin/tests/system/sortlist/clean.sh
	bin/tests/system/stub/clean.sh
	bin/tests/system/xferquota/clean.sh

(cherry picked from commit f9c9fce5c7)

Conflicts:
	bin/tests/system/digdelv/tests.sh
	bin/tests/system/dlzexternal/clean.sh
	bin/tests/system/formerr/clean.sh
	bin/tests/system/resolver/clean.sh
	bin/tests/system/rndc/clean.sh
	bin/tests/system/rrl/prereq.sh
	bin/tests/system/sit/clean.sh
	bin/tests/system/tkey/clean.sh
	bin/tests/system/zonechecks/clean.sh
	lib/export/isc/nothreads/include/Makefile.in

bin/tests/system/allow_query/clean.sh

@@ -23,3 +23,4 @@
 rm -f dig.out.*
 rm -f ns2/named.conf
 rm -f */named.memstats
+rm -f ns*/named.run