Manage Categories - Field Type drop-down should be dependent on Data Type selection.

Currently, when I create a new image category (System Admin > Manage Categories) and select a Data Type other than "String", I still have the option to pick "List" from Field Type, but then I receive an error that I actually can't pick "List". I would expect the "List" option to be hidden from the Field Type drop-down if it's not a valid combination when I select "Numeric", "Decimal" or "Date".  It's misleading users.