Log Message:
Update tokyocabinet to 1.4.23.

Changes:
2009-05-24  Mikio Hirabayashi  <mikio@users.sourceforge.net>

	* tcutil.c (tcmapiterinit2, tcmdbiterinit2): new functions.

	* tchdb.c (tchdbiterinit2, tchdbiterjumpimpl): new functions.

	* tcfdb.c (tcfdbiterinit2, tcfdbiterjumpimpl): new functions.

	* tctdb.c (tctdbiterinit2): new function.

	- Release: 1.4.23