Named objects cannot be passed as selected to update*Input() functions

[nteetor]

The update input functions will convert a named list or vector into a json object instead of an array. On the javascript side there is no .indexOf method for objects. So, if selected is a named object there is no error on the server-side, but there is an error on the client-side.

The simplest solution is to drop any names from the selected values. The coerce_selected() helper would be updated.