resource.calendar.leaves: employee reads own or global
['|', ('resource_id', '=', False), ('resource_id.user_id', 'in', [False, user.id])]
resource.calendar.leaves: employee modifies own
[('resource_id', '!=', False), ('resource_id.user_id', 'in', [False, user.id])]
resource.calendar.leaves: admin modifies global
[('resource_id', '=', False)]
resource.resource multi-company
[('company_id', 'in', company_ids + [False])]
resource.calendar.leaves: multi-company rule
[('company_id', 'in', company_ids + [False])]