[UX] Add an easy-to-use 'Remove' button on appropriate multi-value fields

Widget types that will need this remove button are as follows: - textfield - number - autocomplete (entity/term reference)

I've stumbled across three different modules that are all trying to solve this UI deficiency for fields in general: - the multiple_fields_remove_button module - the cck_multiple_field_remove module - the field_remove_item module