Make it possible to specify test specifi config file as <testname>.cnf

mysql-test/suite/rpl/t/rpl_000015.cnf:
  Use test specific config file
mysql-test/suite/rpl/t/rpl_rotate_logs.cnf:
  Use test specific config file

mysql-test/lib/mtr_cases.pm

@@ -754,6 +754,15 @@ sub collect_one_test_case {
   # ----------------------------------------------------------------------
   process_opts_file($tinfo, "$testdir/$tname-slave.opt", 'slave_opt');
 
+  # ----------------------------------------------------------------------
+  # Check for test specific config file
+  # ----------------------------------------------------------------------
+  my $test_cnf_file= "$testdir/$tname.cnf";
+  if ( -f $test_cnf_file ) {
+    # Specifies the configuration file to use for this test
+    $tinfo->{'template_path'}= $test_cnf_file;
+  }
+
   # ----------------------------------------------------------------------
   # master sh
   # ----------------------------------------------------------------------

mysql-test/suite/rpl/t/rpl_000015-master.opt

---config-file-template=../rpl_1slave_base.cnf
-

mysql-test/suite/rpl/t/rpl_000015.cnf

+!include ../rpl_1slave_base.cnf
+

mysql-test/suite/rpl/t/rpl_rotate_logs-master.opt

--O max_binlog_size=4096
---config-file-template=../rpl_1slave_base.cnf
-

mysql-test/suite/rpl/t/rpl_rotate_logs.cnf

+!include ../rpl_1slave_base.cnf
+
+[mysqld.1]
+max_binlog_size=4096
+
+