De-activate categories for new proposals, maintain them for results and old proposals

It is often the case that within processes or assemblies, categories must be changed, when categories change it is a problem to manage old content, because: 1. Categories cannot be removed, 2. Old content might not match new categories, 3. If old and new categories co-exist they are all (new and old) displayed for new users within the proposal creation wizard and creates confusion. The solution to this problem is to be able to de-activate a category (and its subcategories) so the old content remains categorized under the old category set but new proposals can only categorized within the active categories. Also accountability can continue with the old categories but new ones can be added.