Fixed test suite failures when the auth plugin is not compiled in.
The problem is that the commands COM_STMT_CLOSE, COM_STMT_RESET, COM_STMT_SEND_LONG_DATA weren't being logged to the general log. The solution is to log the general log the aforementioned commands.
Logging behavior changed in early 5.1. (The filename was never right, but the "opt" file is unnecessary in 5.0 anyway.)
