Verify that if Maria table is absent or initially empty, CREATE SELECT and INSERT SELECT with enough
rows cause no logging

mysql-test/include/maria_empty_logs.inc:
  don't assume that mysqltest is the default db
mysql-test/r/maria-no-logging.result:
  result. Without the optimization of disabling logging in ha_maria::start_bulk_insert(),
  we see 24k instead of 16k, in the cases where the table is empty.
mysql-test/r/maria-purge.result:
  side effect of change to maria_empty_logs.inc
mysql-test/t/maria-purge.test:
  maria-purge.test used to fail when run in a group like this "--big t/*maria*.test" because
  SHOW ENGINE MARIA LOGS was influenced by previous tests; deleting logs to fix that.