Log Message:
Changes 5.5.16:
* The default thread-handling model in MySQL Server executes statements using
  one thread per client connection.
* Commercial distributions of MySQL now include two plugins that enable MySQL
  Server to use external authentication methods to authenticate MySQL users
* Important Change: Replication: The RESET SLAVE statement has been extended
  with an ALL keyword.
* A new utility, mysql_plugin, enables MySQL administrators to manage which
  plugins a MySQL server loads.
* Bugs fixed.