COFEAT ( featre, nitems, ifail )
================================

  Count entities in feature

    Can be called from the GO.

Receives:
  KI_tag_feature           *featre         --- feature

Returns:
 <KI_int_nitems>           *nitems         --- number of items in feature
  KI_cod_error             *ifail          --- failure code


Description:
  The number of entities in the feature is returned in 'nitems'.