IDCOFE ( edge, curve, ifail )
=============================

  Identify curve of edge

    Can be called from the GO.

Receives:
  KI_tag_edge              *edge           --- edge

Returns:
  KI_tag_curve             *curve          --- curve
  KI_cod_error             *ifail          --- failure indicator

Specific errors:
  KI_missing_geom           The given edge has no associated curve

Description:
  The curve associated with the given edge is returned.

  It is now possible to represent edges with either a single curve or fin
  curves. This function only supports the single curve case because this is the
  only case for which the curve is associated with edge. OUGEEF should be used
  for accessing the fin curves.