* Use plugin_manager::reset_caches() when changing visibility of plugins.
* Implement new method get_enabled_plugins() method in subplugin info classes.
* Each plugin should include version information in version.php.
+* Module and block tables do not contain version column any more, use get_config('xx_yy', 'version') instead.
DEPRECATIONS:
Various previously deprecated functions have now been altered to throw DEBUG_DEVELOPER debugging notices