Removed usage of @r/result as this made life hard when testing different
table handlers.
Allow concurrent inserts if no update/binary log.
Don't remove key_cache at flush tables.
Fixed bug in SELECT DISTINCT SUM()...
updated manual about table lock counter
fixed coredump in DROP DATABASE with long bogus name by non-root user
fixed bug in handling STOP immediately after ROTATE
added test case for buffer overrun on DROP DATABASE by non-root user
added test case for the STOP bug in replication