WL#3368 mixed format as default

Two minor fixes:
 1. to make make test executes with mixed;
 2. proper isolation of binlog_statement_insert_delayed 
    from others through reset master cleaning up binlog
    todo: adapt this technique to other restarting for binlog tests


Makefile.am:
  Binlog format switches to MIXED. A new Makefile target
  test-binlog-statement 
  is introduced for checking tests requiring exclusive STATEMENT format.
mysql-test/t/binlog_statement_insert_delayed.test:
  cheapest method to clean up binlog after previous tests

Makefile.am

@@ -118,7 +118,7 @@ test-unit:
 
 test-ps:
 	cd mysql-test ; \
-	./mysql-test-run.pl $(force) --ps-protocol --mysqld=--binlog-format=statement
+	./mysql-test-run.pl $(force) --ps-protocol --mysqld=--binlog-format=mixed
 
 test-nr:
 	cd mysql-test ; \
@@ -129,6 +129,10 @@ test-pr:
 	./mysql-test-run.pl $(force) --ps-protocol --mysqld=--binlog-format=row
 
 test-ns:
+	cd mysql-test ; \
+	./mysql-test-run.pl $(force) --mysqld=--binlog-format=mixed
+
+test-binlog-statement:
 	cd mysql-test ; \
 	./mysql-test-run.pl $(force) --mysqld=--binlog-format=statement
 

mysql-test/t/binlog_statement_insert_delayed.test

@@ -3,4 +3,7 @@
 
 -- source include/not_embedded.inc
 -- source include/have_binlog_format_statement.inc
+-- disable_query_log
+reset master; # get rid of previous tests binlog
+-- enable_query_log
 -- source extra/binlog_tests/binlog_insert_delayed.test