DURING INNODB RECOVERY

Problem:
=======
The connection 'master' is dropped by mysqltest after
rpl_end.inc. At this point, dropping temporary tables
at the connection 'master' are not synced at slave.
So, the temporary tables replicated from master remain
on slave leading to an inconsistent close of the test.
The following test thus complains about the presence of
temporary table(s) left over from the previous test.

Fix:
===
- Put explicit drop commands in replication tests so
  that the temporary tables are dropped at slave as well.
- Added the check for Slave_open_temp_tables in
  mtr_check.sql to warn about the remaining temporary
  table, if any, at the close of a test.