Code to define modeltype RM-2380

create a modeltype table used by models and pfts. The table is
initialized with the types already in the models (not pfts). All models
and pfts are associated with a modeltype next.
User can add/edit modeltypes and see the pfts/models associated with it.
In order for sorting the models list on the Type to work properly, you must add "modeltype" to the SEARCH_INCLUDES constant on line 6. (A change to the model index view is needed too.)