CRTOSO ( centre, axis, majrad, minrad, torus, ifail )
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  Create toroidal solid

Receives:
  KI_vec_position           centre         --- centre of torus
  KI_vec_axis               axis           --- axis of torus
  KI_dbl_radius            *majrad         --- major radius
  KI_dbl_radius            *minrad         --- minor radius

Returns:
  KI_tag_body              *torus          --- torus
  KI_cod_error             *ifail          --- failure indicator

Specific errors:
  KI_majrad_minrad_mismatch Major radius not greater than minor radius
  KI_radius_too_large       Minor radius too large
                            Major radius too large

Description:
  A torus is created. Its size and position are equivalent to sweeping a circle
  radius 'minrad' about an axis through 'centre', direction 'axis'. The centre
  of the (swept) circle traces a circular path (the spine circle) of radius
  'majrad'.