OzTheGreat

Adds a multiple select box to every non-admin user profile that allows admins to 
select which languages that user can see / edit in the wp-admin.
Languages that a user cannot see are hidden. If they try to switch surreptitiously 
it will throw an error message.
This plugin REQUIRES WPML and is useless without it.

WPML Editor Languages

Allows admins to restrict users to specific languages in the WordPress admin

Patryk

Add timestamp to style.css link (eg: style.css?1412863646&#038). Also works with child theme style.css

WPML Editor Languages vs PRyC WP: Add timestamp to style.css link