Darts: Double-ARray Trie System

This is a C++ template library that implements Double-Array [Aoe
1989].  Currently only Japanese documentation is provided.

* [Aoe1989] Aoe, J. An Efficient Digital Search Algorithm by Using a
  Double-Array Structure. IEEE Transactions on Software
  Engineering. Vol. 15, 9 (Sep 1989). pp. 1066-1077.

* [Datrie] Theppitak Karoonboonyanan An Implementation of Double-Array
  Triehttp://www.links.nectec.or.th/~thep/datrie/

Author:	Taku Kudoh <taku-ku@is.aist-nara.ac.jp>
WWW:	http://www.chasen.org/~taku/software/darts/