It should not list excluded fields as read only or unique

[atleta]

I don't want read only fields to be displayed (in my case it's just cruft that confuses the user). However, listing them in massadmin_exclude doesn't work, because it's only checked for fields that are not read only or unique.

The order of the checks should be reversed in the template (admin/includes/mass_fieldset.html) so that the first (outermost) if statement verifies if the field is in massadmin_exclude. If not then it can go on to the current logic. This way it's still possible to display the read only and unique fields as such but they can also be hidden by adding them tomassadmin_exclude`.