Allow update to Direct Manager of people

The direct manager of people hasn't any right, he can not manage information from his resources or his teams.

The idea is to allows update all fields from his subordinates as he is a direct manager of the resource or if his the direct manager of a group.
The direct manager of a group could update fields of all team members : update all sections, the calendar of holidays and also all custom fields.
Also he can generate a Grant Access from his subordinate.
Exception: The direct manager can't change Global permission section and he can't change the password and the Username of subordinate.

remark : It could be nice his the Administrators can generate Grant access from all people and not only the user himself, because there is always people shares their login/password because they are in holiday and they forgot the share access.