this changes most visble uses of master/slave terminology in tests.sh
and most uses of 'type master' or 'type slave' in named.conf files.
files in the checkconf test were not updated in order to confirm that
the old syntax still works. rpzrecurse was also left mostly unchanged
to avoid interference with DNSRPS.
(cherry picked from commit e43b3c1fa1)
Including $SYSTEMTESTTOP/conf.sh from a system test's clean.sh script is
not needed for anything while it causes an error message to be printed
out when "./configure" is run, as "make clean" is invoked at the end.
Remove the offending line to prevent the error from occurring.
