IDKYPA ( keylen, key, parts, states, nparts, ifail )
====================================================

  Identify keyed parts.

Receives:
  KI_int_nchars            *keylen         --- length of key
  KI_chr_key                key[keylen]    --- key of part to find

Returns:
  KI_tag_list_part         *parts          --- parts found with given key
  KI_tag_list_int          *states         --- states of parts found
  KI_int_nitems            *nparts         --- number of parts found
  KI_cod_error             *ifail          --- failure indicator

Specific errors:
  KI_key_not_found          part with key not found in memory

Description:
  IDKYPA returns a list of the parts with the given key which are attached to
  the world. A list of the states of the parts is also returned.

  All parts in the world are scanned until a stored, modified or unloaded
  part with the given key is found. New and anonymous parts do not have
  keys and cannot be found with this function.

  There may actually be more than one part with the same key. They are either
  all modified or one is stored/unloaded. In this situation the tags of all the
  parts will be returned.

  If no part with the given key is attached to the world, KI_key_not_found will
  be returned in 'ifail'.