Steps to reproduce the issue

• There are two Events missing in the new Media Manager: onContentBeforeDelete and onContentafterDelete

• These Events need to be triggered both for Files and Folders

old code:

$result = $dispatcher->trigger('onContentBeforeDelete', array('com_media.folder', &$object_file));

This is a B/C break (or since the media manager is brand new degraded DEV expectation)

Expected result

Events triggered when file/directory is deleted

Actual result

No events are emitted

System information (as much as possible)

Additional comments

@wilsonge @laoneo @dneukirchen