Fix for BUG#4971 "CREATE TABLE ... TYPE=HEAP SELECT ... stops slave (wrong DELETE in binlog)":
replacing the no_log argument of mysql_create_table() by some safer method
(temporarily setting OPTION_BIN_LOG to 0) which guarantees that even the automatic
DELETE FROM heap_table does not get into the binlog when a not-yet-existing HEAP table
is opened by mysql_create_table().