In practice this means that handlerton is now created by the server and is passed to the engine. Plugin startups can now also control how plugins are inited (and can optionally pass values). Bit more flexibility to those who want to write plugin interfaces to the database.
remove #define __attribute__(A) from plugin.h
increase API version because placeholders were added
more robust definition of min_plugin_interface_version
duplicate fields removed, st_mysql_storage_engine added to support
run-time handlerton initialization (no compiler warnings), handler API
is now tied to MySQL version, handlerton->plugin mapping added
(slot-based), dummy default_hton removed, plugin-type-specific
initialization generalized, built-in plugins are now initialized too,
--default-storage-engine no longer needs a list of storage engines
in handle_options().
mysql-test-run.pl bugfixes
