It is not possible to prevent the server from starting if a mandatory
built-in plugin fails to start. This can in some cases lead to data
corruption when the old table name space suddenly is used by a different
storage engine.

A boolean command line option in the form of --foobar is automatically
created for every existing plugin "foobar". By changing this command line
option from a boolean to a tristate { OFF, ON, FORCE } it is possible to
specify the plugin loading policy for each plugin.

The behavior is specified as follows:
   OFF   = Disable the plugin and start the server
   ON    = Enable the plugin and start the server even if an error occurrs
           during plugin initialization.
   FORCE = Enable the plugin but don't start the server if an error occurrs
           during plugin initialization.