CRETRA ( direct, dist, transf, ifail )
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  Create a translation transformation.

Receives:
  KI_vec_direction          direct         --- direction
  KI_dbl                   *dist           --- distance

Returns:
  KI_tag_transform         *transf         --- translation transformation
  KI_cod_error             *ifail          --- failure code


Description:
  Calculates a transformation matrix that, when applied to an entity,
  causes it to be translated in the given direction vector by the given
  distance.