Implement test case rpl_gtid_stop_start.test to test normal stop and restart
of master and slave mysqld servers.

Fix a couple bugs found with the test:

 - When InnoDB is disabled (no XA), the binlog state was not read when master
   mysqld starts.

 - Remove old code that puts a bogus D-S-0 into the initial binlog state, it
   is not correct in current design.

 - Fix memory leak in gtid_find_binlog_file().