Add new action 'delete_user_form' in wp-admin/users.php and wp-admin/network/users.php.

Props SergeyBiryukov, usermrpapa.
Fixes #27230.

Built from https://develop.svn.wordpress.org/trunk@28885


git-svn-id: http://core.svn.wordpress.org/trunk@28684 1a063a9b-81f0-0310-95a4-ce76da25c4cd

wp-admin/network/users.php

@@ -77,6 +77,9 @@ function confirm_delete_users( $users ) {
 		}
 	}
 
+	/** This action is documented in wp-admin/users.php */
+	do_action( 'delete_user_form', $current_user );
+
 	submit_button( __('Confirm Deletion'), 'delete' );
 	?>
 	</form>